METHODS AND DEVICES FOR PREVENTION OF HYPOTHERMIA IN A MAMMAL DURING PROLONGED EXPOSURE TO EXTREME COLD
Methods and devices for preventing a change in the core body temperature of a mammal under cold conditions are provided. In the subject methods, a requirement for thermal energy input in said mammal is first detected. In response to the detection of this requirement for thermal energy input, a surface of a portion of the mammal is contacted with a warm temperature medium under negative pressure conditions for a period of time sufficient to introduce thermal energy into the core body of the mammal. The subject devices include at least a means for detecting a requirement for thermal energy input and a means for contacting a surface of the mammal with a warm temperature medium under negative pressure conditions. The subject methods and devices find use in a variety of applications, and are particularly suited for use in maintaining the core body temperature of a mammal substantially constant under cold conditions for an extended period of time.
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;
(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 means for detecting a thermoregulatory error in said mammal.
26 . The device according to claim 25 , wherein said means for detecting a requirement for thermal energy input in said mammal is a vasoconstriction detecting means.
27 . 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.
28 . The device according to claim 22 , wherein said mammal is a human.
29 . The device according to claim 22 , wherein said sealable enclosure has a configuration selected from the group consisting of a sleeve, glove and boot.