WO1994023677A2

WO1994023677A2 - Thermal coverings/wound dressings

Info

Publication number: WO1994023677A2
Application number: PCT/GB1994/000767
Authority: WO
Inventors: Nicholas John Mills
Original assignee: Nicholas John Mills
Priority date: 1993-04-13
Filing date: 1994-04-12
Publication date: 1994-10-27
Also published as: AU6507494A; WO1994023677A3

Abstract

A laminate of a reflective foil of metallised polyester and a heat-softenable polyethylene film is perforated to allow transmission of water vapour and is used as a thermal covering or jacket for animals and humans. The laminate may form a large sheet overprinted with advisory shapes for cutting out to wrap specified body parts. The laminate may also be used as a support for wound dressing with an overprinted camouflage pattern. The laminate may be secured to itself or other surfaces such as under/over blankets or under garments by heat bonding. The reflective metallised film reflects back the body's own heat which is advantageous in wound/burn healing and incorporates a method for visualising the underlying wound/burn.

Description

THERMAL COVERINGS/WOUND DRESSINGS

This invention relates to thermal jackets and covers used to

prevent heat loss from body parts of humans and animals/

especially injured areas.

It is known that up to two thirds of heat loss from a human

body can occur by radiation. To prevent heat loss in extreme

conditions/ it is known to use reflective plastics "space

blankets" as a body wrapping. For the same reasons, sleeping

bags have been constructed from similar material.

A problem with these applications is the trapping of

perspiration and water vapour within the impermeable wrapping.

This is also a problem with use of impermeable materials to

cover injuries such as sprains and wounds.

The present invention provides a thermal jacket or cover for a

body part/ comprising a sheet of reflective metal foil or

metallised plastics film/ the sheet being perforated to allow

water-vapour transmission/ and means for securing the sheet to

a body part or other surface. The jacket or cover may be used generally to prevent heat

loss/ or to shield injuries or wounds in both animals and

humans. For example the perforated sheet may be secured to a

horse blanket or human underwear to prevent loss of body heat/

or used to preserve body temperature in neonates.

Alternatively it may be wrapped round limbs subject to

bruising or sprains to retain body heat or to retain heat

generated by a rubefacient or poultice applied under the

perforated sheet. Similarly it may be used as a cover for

anti-arthritic compositions applied topically or parenterally.

It may also be used to shield wounds and maintain the wound

surface at body temperature to assist healing. In all these

applications/ the reflective material prevents heat loss/

while the perforations prevent build up of water vapour.

The effects of reflecting back the patient's (human or animal)

own infra-red ratiation are to increase tissue temperature/

cause vasodilation and thus increase the local circulation

which aids the delivery of needed tissue nutrients and the

removal of tissue waste products. The jacket may be used to prevent "cold-start" strains. It

has an enhancing effect when used prior to massage and

exercise. It may also be applied after an acute injury to

decrease swelling/ pain and muscle spasm.

When a metal foil/ such as aluminium foil, is used, the foil

is preferably laminated to one or more supporting plastics

films/ the perforations passing through the whole

laminate. Most conveniently a metallised plastics film is

used, preferably an aluminised polyester film.

The jacket or cover may be used in sheet form, or more

preferably is shaped so as to fit comfortably around a body

part/ such as parts of human or animal limbs. The jacket or

cover may be provided ready shaped/ or as a sheet printed with

a guideline shape for the user to cut out. In sheet form it

may also be used as an underblanket for bedding.

In an advantageous form of the invention a rectangular sheet

is printed with the outlines of several appropriate shapes for different body parts, allowing the user to cut out whichever

is needed.

The securing means may be an adhesive tape/ such as

conventional surgical tape, which may simply be wrapped around

the jacket once it is in position on a body part.

Double-sided adhesive tape is especially suitable, as it may

be used to secure the reflective sheet directly to an existing

body cover such as an animal blanket or human underwear. For

example a suitably shaped sheet may be secured to underside of

a. horse or dog blanket by double-sided adhesive tape, between

the blanket and the animal. Alternatively it may be attached

to a human under-vest/ between the vest and ou er clothing/ or

to a T-shirt, or secured in shoes as insole.

Double-sided tape may also be used to secure overlapping sheet

portions when the reflective sheet is wrapped round a limb.

On occasion it may be possible to secure the reflective sheet

directly to a body using double-sided tape. The adhesive tape is preferably hypo-allergenic if it is likely to come

into direct contact with the skin.

Since the tape may block perforations provided to allow

passage of water vapour, the perforations are preferably

arranged in discrete bands across the jacket in a ratio of

perforated to unperforated bands that will allow an

appropriate transmission of water vapour in most

configurations. Then the adhesive tape may be applied to

unperforated areas and thus not impede the vapour

permeability.

In a situation where an impermeable jacket is required extra

lengths of adhesive tape may be applied across the perforation

bands to seal the perforations. Also in some situations it

may be advantageous to omit the perforation altogether.

The reflective film or foil may be printed on its external

surface with instructional material, or decorative or

promotion material. As indicated above, for convenience, especially when intended

for use as .a heat loss jacket, the foil or film may be

provided in large sheets for the user to cut to shape as

desired, preferably with over printed shapes as guidance to

useful application. This would suit use by, for example, a

veterinary practitioner with a non-predictable workload.

However for known regularly occurring uses it will be

convenient to provide pre-shaped jackets, and in this

situation it may be useful to attach ribbons or straps as

sealing means. Alternatively adhesive tape can be

preaffixed/ with protective strips covering adhesive surfaces.

In an advantageous embodiment the foil or film comprises a

laminate of aluminium foil or a metallised film and a

heat-softenable polymer film/ for example of polyethylene.

In this embodiment the reflective film may be secured to an

underlying substrate, such as an animal blanket or human

undergarment, by heat-pressing. Most conveniently this is

achieved by placing the polymer coating against the substrate and applying a domestic iron or other heat source to the

metallic side of the laminate, taking care to avoid as much as

possible the perforated regions so that the porosity is not

reduced by blocking the perforations with softened polymer. By

heat bonding the sheet to a layer of absorbent paper, the foil

or film may advantageously be used as a protective sheet for

use on a medical examination couch.

In a further advantageous embodiment the perforated, reflective

film is used as backing material for a conventional wound

dressing, providing protection and preventing heat loss while

allowing the wound to "breathe". A conventional wound dressing

composition or pad may be adhered to the reflective film, or

the reflective film may be placed on top of a pre-applied

dressing. If waterproofing is needed, adhesive tape can be

used to seal the perforations.

When used as a support for wound dressing/ the cover is preferably provided in shapes suited to a specific

application, so that they can be applied immediately when

needed.

The wound dressing aspect of this invention may advantageously

be applied to military use, since the film or foil may be

overprinted on its external surface with a camouflage pattern

or a high-visibility recognition pattern or a radar reflective

pattern. Therefore in a battle situation, protective clothing

can be cut away from a wound/ and replaced by a wound dressing

having a perforated reflective film backing with the

over-printed surface facing outwards.

In a situation where impermeable protection is needed/ for

example where chemical attack is anticipated/ the porous bands

can be sealed completely with adhesive tape as described

above_; and tape can be used to seal the overlap of dressing

and clothing completely. Advantageously charcoal is incorporated in the dressing, or as a layer interposed between

the dressing and the backing film, as an absorbent for

chemicals. In a medicated wound dressing system it may be

advantageous to omit perforations to ensure impermeability.

The perforations required by many embodiments of the invention

may be conveniently formed by needle punching the reflective

foil or film, or alternatively perforations may be formed by

punching out small slits or slots. In a preferred embodiment

rows of perforations at the same spacing are staggered to give a

quasi-hexagonal effect with a perforation in the centre of the

hexagon. This effect may be provided over the whole sheet, or

overall except for edge areas or in the bands described above.

The perforation for passage of water vapour are most

conveniently formed by needle punching/ typically by passing the

foil or film over a roller studded with protruding needles at

the desired spacing and pattern. Advantageously the needles are inclined to the roller surface, typically at about 5° from

the vertical.

To increase permeability it may be advantageous to punch out

circles rather than increase the needle size, since larger

needle-punched holes may close up in use. In punching out

circles care must be taken not to remove too much material

overall/ since this will reduce the reflective area.

As a means for increasing permeability while retaining

reflectivity, a sheet of this invention, perforated or

unperforated/ may be sliced into strips/ and the strips woven

together to form a sheet of overlapping strips. The strips may

be heat bonded to each other at spaced contact points/ providing

greatly increased permeability through the weave structure/

while retaining substantially full overall reflectivity.

In a variation of this embodiment/ the strips may be stamped out of a sheet, forming open slots but leaving an untouched

edge strip, which mantains the integrity of the sheet. The

stamped-out strips can be woven back into the sheet transverse

to the material left between the slots. Alternatively two

slotted sheets can be overlapped and heat bonded together at

spaced contact points.

In a further application of the invention, the perforated

metallised film may be used as a jacket for a composting

system. The jacket reflects the infra-red radiation produced

by the decomposing vegetation while the perforations allow

excess moisture to escape.

The invention is further illustrated by the accompanying

drawings in which:

Fig. 1 : is a schematic side view of a needle punching system.

Fig. 2a and 2b : each show a perforated film or foil.

Fig. 3a and Fig. 3b : each show a sheet of film or foil with printed shapes to assist the user: (a) for veterinary use

(b) for human use.

Fig. 4 : shows a section through another emodiment of

battlefield dressing.

Fig. 5 : shows a section through another embodiment of

battlefield dressing.

Fig. 6 : shows a perspective view of a method of storing a

battlefield dressing.

Fig. 7 : shows a perspective view of a wound dressing or

poultice 32 which is heat-bonded or joined by a peelable

lacquer to a perforated layer 33 which in turn is bonded to a

non-perforated layer.

Fig. 8 : shows a schematic view of a burns dressing which

incorporates alternating metallised 36 and transparent 35

areas.

Fig. 9 : shows an arrangement wherby a wound contact layer 39 is bonded to a transparent polyester/polythene film which in

turn is joined by a specialised peelable lacquer to a

reflective metallised film, 41.

Fig. 10 : shows a reflective metallised film layer 41 which is

bonded by suitable peelable lacquers to a transparent

polyester/polythene layer which is produced in the form of a

glove.

Referring to Fig. 1 of the accompanying drawings, a driven

roller 20 is drilled to receive needles 21 which cover the

surface longitudinally and circumferentially. The needles

are held in position by an adhesive.

A film or foil requiring to be perforated is passed over the

roller and needles, and auxiliary roller 23,24 press the film

22 into contact with the needles. The needles pass through

the film to form perforations. As shown in the enlarged area

the needles are preferably inclined to the roller surface at approx. 5° to the radius. This allows easier separation of

the needles from the film after perforation and has been found

to form perforations that are less likely to close up during

use.

Using a roller of approx. 76mm diameter/ it has been that the

needles protruding by about 5mm and 0.75mm diameter give a

satisfactory perforation. Typically the needles are spaced

approx. 10mm from each other. The positioning of the needles

can be adjusted to achieve desired perforation patterns.

As shown in Fig. 2a a heat-loss cover or jacket of this

invention is based on a sheet 1 of polyester film metallised

with aluminium by vapour deposition to produce a reflective

coating. The laminate is perforated by needle punching as

described above. The perforations may be disposed in

staggered rows give a hexagonal layout as shown in the

enlarged section 1. Typically the perforations are at a

spacing of approximately 1cm. As shown in Fig. 2b the

perforations may be concentrated in discrete bands 4 at spaced

intervals over the sheet. Fig. 3a hows a sheet of metallised film or foil printed

appropriately.for veterinary use. The over-printing provides

advisory shapes to be cut out for use as heat-loss protection

under horse blankets and dog jackets/ and for use in treatment

of limb injuries.

Fig. 3b shows a sheet similarly over-printed with advisory

shapes for human use.

The cut-out shapes may be adhered to the intended substrate

using double-sided adhesive tape. When the sheet is a

laminate of metal foil or a metallised film and polyethylene

or another softenable plastic film/ the sheet may be adhered

by application of a heated iron/ applying the iron to the

metal side. When the perforations are bonded the heat

bonding may be restricted to in the unperforated regions so as

to maintain the desired porosity.

A suitable film for use in this invention is a metallised 12

micron polyester film, in which the base film is biaxially oriented unplasticised polyester, as supplied for example by

Hueck et Cie. The metallisation is typically approximately

120 mg/m.2 . Suitably the film has a melt index of

approximately 250%. Advantageously a layer of polyethylene,

typical from 25 - 75 micron thick, is laminated to the base

film. Such a laminate may be adhered to a substrate by

hot-pressing using a domestic clothes iron, and may

subsequently be stripped from the substrate without residue

problems.

Referring to Fig. 4 a wound dressing comprises an assembly of

three layers 11,12,13 of metallised polyester/polyethylene

laminate and two wound contact dressings 14,15. Each film

11,12/13 has its polyethylene surface 11a/12a/13a facing into

the assembly and each wound dressing 14/15 has its wound

contacting surface 14a/15a facing outwards. The dressing is

shown schematically with spaced layers so that the structure

can be seen. In the actual construction/ starting from the

left hand side (as seen in Fig. A) , an unperforated film 11 is heat bonded to a perforated film 12 which is heat bonded to

the first wound dressing 14. From the right hand side/ an

unperforated film 13 is heat bonded to the second wound

dressing 15. The two wound dressings are connected at their

non-wound contacting surfaces. Alternatively a single wound

dressing with a double sided wound contacting surface may be

used. The films 12/13 are heat welded to each other at their

contacting surfaces above and below the wound dressing to

provide a sealed and sterilisable package. Alternatively

peelable lacquers can be used to join these films together.

A series of packages may be formed in a continuous strip by

spacing wound dressings between the metallised films and

contacting the assembly with heated rollers or plates to

provide continuous or spaced heat welding as appropriate.

Alternatively special peelable lacquers can be used. The

outer metallised surfaces of each film 11/13 can be printed

using conventional procedures with a camouflage pattern. In a conventional warfare scenario, the outer layer 11 can be

peeled away from later 12, and layer 13 can be peeled away

from layer 13 and wound dressing 15. Thus the perforated,

camouflage-printed film 12 and the dressings can be placed

over the wound. The perforated camouflage layer acts as the

backing layer for the wound dressing system. This perforated

layer allows the wound to "breath" and is suitable as a wound

dressing in conventional warfare.

In chemical and nuclear warfare/ special protective suits are

worn to protect the individual. In such conditions the

unperforated layer 11 and perforated layer 12 can be peeled

away together . from wound dressing 14 and unperforated layer

13. The unperforated layer 13 with its camouflaged outer

surface and the wound dressing are used to dress a wound.

The remaining joined layers 11 and 12 can be used as a strong

unperforated layer to repair the protective suit/ using

suitable adhesive tape. An alternative configuration uses an additional perforated

layer 16 as shown in Fig. 5, to form a symmetrical packing

sequence. This allows peeling to be initiated from either

side. Fig. 5 also illustrates at 17 a feature which may be

applied to other embodiments, namely that unbonded flaps or

tags may be formed, without prejudicing the seal of the wound

dressing. These flaps may be printed on their inner surfaces

with information relating to use of the dressing, in

particular information as to where peeling should be initiated

depending on the prevailing conditions of attack i.e.

chemical/ nuclear or conventional.

As mentioned above/ the dressing system can be supplied as a

continuous strip/ and dressings can be cut away as needed.

Such a strip is conveniently provided as a foil 30 secured by

an external ring 31/ conveniently a roll of adhesive tape for

securing the dressings/ as shown in Fig. 6.

Fig. 7 : illustrates how any wound dressing or poultice system can be backed by a perforated layer 33 and this in turn can be

covered by a nonperforated layer 34. The two layers 33 and

34 can be joined to each other using peelable lacquers. This

arrangement means that the non-perforated layer can be peeled

off the underlying perforated layer 33 when the poultice/wound

dressing is to be used in its dry application and the

non-perforated layer 34 can be left in place when it is

required to have a wet dressing. The non-perforated layer 34

would not be moisture permeable and hence would enable a 'wet'

dressing to stay wet.

There cam be a further adaptation of the design for the

aforementioned military wound dressing in that the metallised

reflective film which is printed with the camouflage pattern

and which forms the backing for the military wound dressing

can be produced from a special film produced by CAMVAC Ltd./

Thetforfl. East Anglia. This special film is produced as

alternating layers of transparent and metallised film. The

proportion of transparent to metallised parts can vary but a typical example would be % metallised film and \ transparent

film.

The transparent part of the film can in turn be covered by a

further reflective film which can be joined to the underlying

film using peelable lacquer.

This covering metallised film can be printed with camouflage

pattern to match up with the camouflage pattern of the

remaining wound dressing backing film.

The advantage of this system is that the upper layer overlying

the transparent layer and attached using peelable lacquer can

be peeled away leaving the transparent layer through which

the primary wound contact layer can be visualised.

Using this method the wound contact layer can be seen and used

to assess the level of haemorrhage from the wound or the state

of the wound without causing disturbance to the wound. The use of the special metallised film as produced by CAMVAC

Ltd., Thetford, East Anglia, which is produced as a

part-metallised and part-transparent film can be used for a

variety of other uses in the area of "thermal coverings".

A typical use is as a reflective cover for baby milk bottles.

The special metallised film can be made as a surrounding

reflective, metallised layer for a baby's milk bottle. The

reflective metallised film can be formed as a close-fitting

covering or pouch for a baby's bottle. The reflective

metallised film reflects back the radiative heat from the warm

milk.

Due to the design of the specialised metallised film produced

e.g. by CAMVAC, Thetford, East Anglia who produce a film that

is part-metallised and part-transparent, the current invention

describes a covering of the transparent part of the film by a

further metallised strip which can be printed with any design

or operating instructions.

When this further metallised strip is in place it reflects back the radiative heat from the milk.

However if it is required to see the level of milk in the

bottle then the metallised strip which is joined to the

underlying metallised layer by peelable lacquer can be peeled

back for effective visualisation.

The general design of this reflective metallised film whereby

a transparent strip of the underlying film is covered by a

further layer of metallised film which is able to reflect back

the infra-red radiation. This further layer of reflective

metallised film is joined to the underlying film by peelable

lacquer.

This basic design is suitable for use in any case where a

reflective film can be used to reflect back - radiant heat

(normally infra-red radiation) and yet to visualise the

underlying structure. A further embodiment of this invention relates to a wound or

burns dressing which reflects back the body's own infra-red

radiation by means of a metallised reflective film. This

invention also allows the wound to be visualised whilst the

wound dressing is still in place.

It is well established that wounds and burns heal more quickly

if the wound or burn is kept at body temperature. By

definition when wounds or burns occur the integrity of the

skin is damaged and also the body's ability to maintain body

temperature in that damaged area.

This invention uses reflective metallised film to reflect back

the body's own infra-red radiation in order to maintain the

body temperature in the area of a wound or burn.

This invention also incorporates methods of visualising the

wound area whilst the reflective metallised film is present in

order to minimise disturbance of the wound dressing. The

visualisation can be achieved as follows: In the first method, the reflective metallised

polyester/polythene film can be produced in alternating strips

of metallised film and transparent layers. Such an

alternating metallised and then transparent film is produced

in various thicknesses (e.g. 38 micron) by e.g. CAMVAC Ltd.,

Thetford, E. Anglia/ U.K.

Such a film can be made so that the reflective metallised part

covers two-thirds of the area while the transparent part

covers one-third of the area or in fact the film can be made

with any proportion of metallised to transparent area.

The aim of this burn or wound dressing is to reflect back the

body's own infra red radiation to decrease the heat loss from

the wound burn area and to maintain body temperature at the

wound/burn surface. The transparent polyester/polythene part

of this wound/burn dressing enables the wound/burn to be

visualised.

This polyester/polythene film which has both a reflective metallised part as well as a transparent part can be heat

bonded to itself to form a "mitten" shape or a "glove" shape

or a "foot" shape or a "tube" shape/ in fact to any shape

which might be useful for a wound/burn dressing.

Such mittens or gloves can be partially bonded to a paper

backing as in the method used in the Dispos-a-glove*

arrangement for an examination glove. (Dispos-a-glove is a

trademark of Johnson & Johnson Medical). This method means

that the glove or mitten or tube can be put on easily.

Such an arrangement of alternating metallised 36 and

transparent areas 35 are shown in Fig. 8 which shows a

dressing in the form of a mitten.

If it is decided to produce a specialist burn dressing in the

form of such a mitten/ the mitten can be sealed 37 and be

opened by a tab 38. Instructions can be printed on the

inside or outside of this tab.

The mitten can be filled with a suitable pharmaceutical burns therapeutic agent e.g. Flamazine* (antibacterial, silver

sulphadiazine 1% cream). (Trade mark Smith & Nephew

Pharmaceuticals). Such a dressing could be used for skin

graft donor sites, wounds, burns, infected leg ulcers and

pressure sores.

Either side of the mitten can be printed using specialised

foil printing technique as developed by G & A Printers, Unit

15c Eurolink Industrial Centre, Sittingbourne, Kent. E.G.

the inside of the tab 38 can be printed with the instructions

for use. The outside of the mitten over the metallised area

can be printed with company logos, further instructions, or

even with any variety of camouflage printing so that the

dressing could be specially adapted for military use.

A second method of producing a wound/burn dressing has a

metallised reflective film to reflect back the body's own

infra-red radiation is as shown in Fig. 9 in which 39

represents the wound contact layer, 40 is a transparent

polyester/polythene film joined by specialised peelable lacquers to the metallised reflective film 41. A specialist,

reflective wound/burn dressing is thus produced.

This reflective metallised film dressing can be made in

virtually any configuration e.g. Fig. 10 - showing a

reflective metallised film layer 41 which is bonded by

suitable peelable lacquers to a transparent

polyester/polythene layer which is produced in the form of a

glove.

The outside of the metallised layer 41 can be printed with any

company logo, directions for use or with camouflage printing

(to make the dressing suitable for military use).

For a specialist burn dressing this dressing can be filled

with any special burns pharmaceutical therapeutic agent e.g.

Flamazine (Smith & Nephew Pharmaceuticals). This specialist

burn dressing can be sealed for e.g. at the "wrist" of the

mitten or glove design. The whole dressing can be sterilised

using gamma irradiation. An alternative design for this reflective wound/burn dressing

is as a combination of the two basic designs in which the

reflective metallised polyester/polythene film is produced in

the form of alternating strips of metallised film and

transparent layers as produced by Camvac Ltd., Thetford, East

Anglia, U.K.

In this design the transparent strips are covered by

reflective metallised strips. These reflective metallised

strips are joined to the underlying polyester/polythene film

using specialised peelable lacquers.

This design, where the reflective metallised strips cover the

transparent strips represents an economical use of materials

and also produces a relatively lightweight dressing. The

underlying dressing with the alternating metallised and

transparent strips is left in place to cover a wound or a

burn. The reflective metallised film reflects back the

body's own infra-red radiation to maintain the wound or burn temperature at an ideal temperature for optimum wound repair.

The bonded, peelable strips can be peeled back to visualise

the wound through the transparent strips without disturbing

the wound/burn.

It is possible to incorporate these designs for reflective

metallised film into the backing layer of occlusive or

partically occlusive dressings e.g. as a backing layer for

Opsite (Smith & Nephew Pharmaceuticals) and Allevyn (Smith &

Nephew Pharmaceuticals). Such a design would improve the

performance of these dressings in respect of maintaining the

temperature of the wound or burn surface at as close to

optimum temperature as possible for maximum healing rates.

A typical example of the peelable lacquer mentioned in this

invention is "Heat Seal 200101" produced by Swale Coatings &

Inks Limited.

This heat-sealable lacquer is a solvent based heat seal for

polyester. This solvent was originally designed for plated metal applications. The heat seal is based on ethyl

acetate and is designed to seal to itself only.

This heat seal for polyester offers excellent adhesion to

treated and untreated polyester with good seal strengths at

low temperatures, (the heat seal threshold being 70°C).

The dry components comply to F + D.A. 175.300.

This heat seal is normally used in conjunction with a

release lacquer when blocked against unprinted polyester.

This heat seal typically has- a total solids content of

25.0%, a viscosity of 20 seconds Zahn 3 at 20°C it is

normally applied by a gravure plate at a recommended dry

coating weight of 1.0 - 1.5 grams per square metre.

31A

A reflective metallised film as described in this invention

can be laminated on the back of an adhesive occlusive

dressing such as op-site film (made by Smith _. Nephew Ltd.)

in order to improve the dressings' characteristics

particularly as a burns dressing. The laminated metallised

film can also be laminated in the form of alternating

transparent strips and reflective metallised strips as

described earlier. The transparent strips can be covered

by further reflective metallised strips which can be

attached by specialist peelable lacquers.

Claims

32CLAIMS :

1. A thermal cover sheet comprising a sheet of reflective metal foil or metallised plastics film, which is perforated to allow passage of water vapour.

2 A thermal cover sheet according to Claim 1, which is printed with outline shapes suitable, when cut out, for covering body parts.

3. A thermal cover sheet according to Claim 1, which is shaped to fit on or around a body part.

4. A thermal cover sheet according to any one of Claims 1 to 3, in which the perforations are arranged in discrete bands across the sheet.

5. A thermal cover sheet according to any one of Claims 1 to 4, in which the perforations are arranged in hexagonal or staggered arrays.

33 6 A thermal cover sheet according to any one of Claims 1 to 5, including means for securing the sheet to a body part or other surface.

7. A thermal cover sheet according to Claim 6, in which the securing means is adhesive tape.

8. A thermal cover sheet according to Claim 6, in which the securing means is a ribbon or strap.

9. A thermal cover sheet according to Claim 6, in which the securing means is a heat-softenable polymer layer on one surface of the reflective foil or film.

10. A thermal cover sheet according to any one of claims 3 to 9, further including a wound dressing pad adhered to the sheet.

11. A thermal cover pack comprising a sheet as claimed in any one of Claims 1 to 5 and a supply of adhesive tape.

12. A wound dressing comprising a wound contacting pad and a

backing sheet of reflective metal foil or metallised plastics

film.

13. A wound dressing according to Claim 12 in which the

reflective backing sheet is perforated to allow passage of

water vapour.

14. A wound dressing according to Claim 13 in which the

perforations are arranged in discrete bands across the backing

sheet.

15. A wound dressing according to Claims 12,13 or 14, in which

the area of the backing sheet is greater than the area of the

wound contacting pad.

16. A wound dressing according to any one of Claims 12 to 15,

in which the outer surface of the backing sheet is printed with

a camouflage pattern.

17. A wound dressing according to Claim 13 which is sealed in

an envelope formed by two opposed unperforated films

sandwiching the perforated film and dressing pad the

unperforated and perforated films being independently peelable

from the combined structure. 35

18. A wound dressing according to Claim 17 in which the

perforated and unperforated films are laminates of a metallised

plastics film and heat-softenable plastics film.

19. A wound dressing according to Claim 17 in which the

unperforated and perforated films are independently peelable

from the combined structure using peelable lacquers.

20. A wound dressing according to Claim 17 in which the

underlying perforated and/or the overlying non-perforated layer

can incorporate a transparent layer so that the primary wound

contact layer can be visualised.

21. A wound dressing according to any one of Claims 12 - 20 in

which the backing sheet is a part-metallised, part-transparent

film which can be used to reflect back radiative heat and yet

allow visualisation of the underlying structure.

22. A wound or burns dressing according to Claim 20 in which

the transparent areas can be covered with further reflective

metallised film which can be peeled back using peelable 36

lacquers to see through the underlying transparent areas which

would enable the level of wound haemorrhage to be assessed or

to assess the state of the wound without causing disturbance of

the wound.

23. A wound dressing according to any one of Claims 12 - 22 in

which a backing layer of reflective metallised film reflects

back the body's own infra-red radiation in order to maintain

the body temperature in the area of a wound or burn.

24. A wound dressing according to any one of Claims 12 - 23

which is heat bonded to itself to form a mitten, glove, foot or

tube shape.

25. A wound dressing according to any one of Claims 12 to 24

which is partially bonded to a paper backing for ease of use.

26. A wound dressing according to any one of Claims 12 - 24

which can be sealed.

27. A wound dressing according to Claim 26 which contains a

useful pharmaceutical agent. 37

28. A wound dressing according to any one of Claims 12 - 27

which has printed instructions on the outside surfaces and on

the opening tabs.

29. A wound dressing according to Claims 12 - 28 which can be

sterilised by gamma irradiation.

30. A wound dressing according to Claims 12 - 29 which is

camouflage printed on the outside for military use.

31. A thermal cover made of part-metallised, part-transparent

film which can be used to reflect back radiative heat and yet

allow visualisation of the underlying structure.

32. A thermal cover according to Claim 30 where the

transparent areas can be covered with further reflective

metallised film which can be peeled back using peelable

lacquers to see through the underlying transparent areas.

33. A thermal cover according to Claims 30 or 31 shaped as a

reflective cover for a hot beverage container, for example a

baby's milk bottle.