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

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

• (a) monitoring said mammal during said temporal duration for the presence of a thermoregulatory error by detecting the presence of vasoconstriction in said mammal;
• 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;
• wherein said cold conditions are in water or at about 30 degrees Fahrenheit or less and wherein the core body temperature of said mammal is maintained substantially constant during said temporal duration.

A method for maintaining the core body temperature of a human substantially constant for a temporal duration of at least about 60 mm 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;
• wherein said cold conditions are in water or at about 30 degrees Fahrenheit or less and wherein the core body temperature of said human is maintained substantially constant during said temporal duration.

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 is a vasoconstriction detecting means;
• (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 to substantially maintain constant the core body temperature of said mammal in cold conditions in water or at about 30 degrees Fahrenheit or less.