Self-activated cooling device

1. A cooling device, comprising:

a shell member having an outer face and an inner face disposed against a surface to be cooled in use of said device, said shell member defining an interior space;

a cooling substrate combination disposed within said interior space, said cooling substrate comprising a first absorbent web of porous material having a first cooling composition applied thereto in a dried substantially film-like network distributed throughout said web, said cooling composition comprising a cooling agent that is activated by contact with an aqueous liquid and a hydrophobic agent present in an effective amount to inhibit wetting of said web and prolong a cooling reaction generated when said substrate is contacted with the aqueous liquid;

an aqueous liquid source disposed within said interior space and separated from said first cooling substrate by a barrier member; and

said device activated by manual manipulation to breach said barrier member causing liquid from said liquid source to move within said interior space to contact and activate said first cooling composition whereby a cooling reaction is generated.

2. The cooling device of claim 1 , wherein said first cooling composition is applied to said absorbent web as an aqueous solution that dries to form said film-like network.

3. The cooling device of claim 1 , wherein said cooling agent comprises one of an inorganic salt or an organic material, and said hydrophobic agent comprises a polymer emulsion that decreases the wettability of said absorbent web.

4. The cooling device of claim 3 , wherein said cooling agent comprises at least about 50% by weight of said cooling composition, and said hydrophobic agent comprises between about 0.5% to about 10.0% by weight of said first cooling composition.

5. The cooling device of claim 1 , wherein said first cooling composition produces a first cooling profile, and wherein said cooling substrate combination further comprises a second cooling composition that produces a second cooling profile that is more rapid as compared to said first cooling profile, said second cooling composition comprising a cooling agent that is activated by contact with an aqueous liquid upon activation of said device.

6. The cooling device of claim 5 , wherein said second cooling composition further comprises a lesser amount of hydrophobic agent than said first cooling composition.

7. The cooling device of claim 5 , wherein said cooling substrate combination further comprises a second absorbent web of porous material within said interior space, said second cooling composition applied to said second absorbent web in a substantially film-like network distributed throughout said porous material.

8. The cooling device as in claim 1 , wherein said shell member comprises a flexible and conformable sleeve member that conforms around an object to be cooled, said first cooling substrate comprising a flexible material so as to conform with said shell member around the object.

9. The cooling device as in claim 1 , wherein said liquid source comprises at least one bladder inserted into said interior space, said bladder separating or breakable upon manual manipulation of said device.

10. The cooling device as in claim 1 , further comprising any combination of insulation material layers and thermal conductive material layers within said interior space so as to direct the generated cooling effect to said inner face.

11. The cooling device as in claim 1 , wherein substantially all of said liquid from said liquid source is absorbed by said cooling substrate combination so that excess liquid is not held within said interior space after activation of said device.

12. The cooling device as in claim 1 , wherein said cooling substrate combination comprises a separate material disposed within said interior space between interior faces of said shell member.