Methods and devices for prevention of hypothermia in a mammal during prolonged exposure to extreme cold

1. A method for preventing a change in the core body temperature of a mammal under cold conditions, said method comprising:

(a) detecting a requirement for thermal energy input in said mammal; and

(b) contacting a surface of a portion of said mammal in response to the presence of said requirement with a warm temperature medium under negative pressure conditions for a period of time sufficient to introduce thermal energy into the core body of said mammal;

whereby the core body temperature of said mammal is prevented from changing under said cold conditions.

2. The method according to claim 1 , wherein said requirement is detected by detecting the presence of a thermoregulatory error in said mammal.

3. The method according to claim 1 , wherein said thermoregulatory error is detected by detecting the presence of vasoconstriction in said mammal.

4. The method according to claim 1 , wherein said method further comprises enclosing said portion of said mammal in a sealed enclosure to produce an enclosed portion of said mammal.

5. The method according to claim 1 , wherein said method is a method of maintaining said core body temperature of said mammal substantially constant for a temporal duration of at least about 60 min and said method comprises performing steps (a) and (b) at least twice during said temporal duration.

6. The method according to claim 1 , wherein said portion of said mammal is a limb or a portion thereof.

7. The method according to claim 6 , wherein said limb is selected from the group consisting of an arm and a leg.

8. The method according to claim 4 , wherein said sealed enclosure has a pressure ranging from about −20 to −80 mm Hg.

9. The method according to claim 1 , wherein said warm temperature medium has a temperature ranging from about 44 to 48° C.

10. The method according to claim 1 , wherein said period of time ranges from about 1 to 600 min.

11. The method according to claim 1 , wherein said mammal is a human.

12. A method for maintaining the core body temperature of a mammal substantially constant for a temporal duration of at least about 60 min under cold conditions, said method comprising:

(a) monitoring said mammal during said temporal duration for the presence of a thermoregulatory error; and

(b) contacting a surface of an enclosed portion of said mammal in response to the presence of said thermoregulatory error with a warm temperature medium under negative pressure conditions for a period of time sufficient to introduce thermal energy into the core body of said mammal;

whereby the core body temperature of said mammal is maintained substantially constant during said temporal duration.

13. The method according to claim 12 , wherein said thermoregulatory error is detected by detecting the presence of vasoconstriction in said mammal.

14. The method according to claim 12 , wherein said method further comprises enclosing said portion of said mammal in a sealed enclosure to produce an enclosed portion of said mammal.

15. The method according to claim 12 , wherein said portion of said mammal is a limb or a portion thereof.

16. The method according to claim 15 , wherein said limb is selected from the group consisting of an arm and a leg.

17. The method according to claim 14 , wherein said sealed enclosure has a pressure ranging from about −20 to −80 mm Hg.

18. The method according to claim 12 , wherein said warm temperature medium has a temperature ranging from about 44 to 48° C.

19. The method according to claim 12 , wherein said period of time ranges from about 5 to 600 min.

20. The method according to claim 12 , wherein said mammal is a human.

21. A method for maintaining the core body temperature of a human substantially constant for a temporal duration of at least about 60 min under cold conditions, said method comprising:

(a) monitoring said mammal during said temporal duration for the presence of a vasoconstriction; and

(b) contacting a surface of an enclosed portion of said mammal in response to the presence of said vasoconstriction with a warm temperature medium under negative pressure conditions ranging from about −20 to 80 mm Hg for a period of time ranging from about 1 to 600 min;

whereby the core body temperature of said human is maintained substantially constant during said temporal duration.

22. A device for introducing thermal energy into the core body of a mammal under cold conditions, said device comprising:

(a) a means for detecting a requirement for thermal energy input in said mammal, wherein said means for detecting a requirement for thermal energy input in said mammal is a means for detecting a thermoregulatory error in said mammal;

(b) a sealable enclosure for enclosing a portion of said mammal;

(c) a means for producing negative pressure conditions in said sealable enclosure; and

(d) a warming means for producing a warm temperature medium in said sealable enclosure.

23. The device according to claim 22 , wherein said portion of said mammal is a limb or portion thereof.

24. The device according to claim 23 , wherein said limb is selected from the group consisting of an arm and a leg.

25. The device according to claim 22 , wherein said means for detecting a requirement for thermal energy input in said mammal is a vasoconstriction detecting means.

26. The device according to claim 22 , wherein said means for producing a negative pressure in said sealable enclosure is capable of producing a negative pressure ranging from about −20 to −80 mm Hg.

27. The device according to claim 22 , wherein said mammal is a human.

28. The device according to claim 22 , wherein said sealable enclosure has a configuration selected from the group consisting of a sleeve, glove and boot.