7. What are some medical concerns for extremely cold weather?
The thing we see most often down here is Frostbite! Please see the prior post on frostbite for more information.
Aside from frostbite, we worry about hypothermia (low body temperature). Our bodies core temperature is regulated to maintain a body temperature around 36.5 degrees C (98 degrees F) by balancing heat production with heat loss. Heat loss is through conduction, convection, radiation and respiration. Our brain controls temperature (thermoregulation) by preserving heat (changing behavior or constricting vessels and shunting to core organs). Temp is also controlled by heat production, such as shivering. Vasoc0nstriction happens before shivering, which is a last resort mechanism to increase body temperature. The best ways for you to increase heat production when you get cold is eating (fuel), staying well hydrated, and keeping active. In healthy adults in cold weather, hypothermia is caused by decreased heat production or increased heat loss. The best way to prevent getting cold, is dressing appropriately for the weather and the conditions!
Symptoms of Mild Hypothermia (32-38 degrees C): Fumbling with zippers, Stumbling, Altered Judgement. Can usually compensate at this stage, and if caught early can be rewarmed with food, movement, and increased layers.
Symptoms of Moderate Hypothermia (28-32 degrees C): Mood Changes, Irritability, Poor Judgement, slurred speech, loss of balance/coordination. May see paradoxical undressing (taking clothes off after prolonged cold stress). The body can no longer produce heat through shivering.
Severe Hypothermia (<28 degrees C): Symptoms above, loss of consciousness at <27 degrees C
Treatment is to warm patients gradually. In the field, change wet clothes to dry clothes (lose more heat through wet clothes.) Catch it early!! In our clinic here, we use warm blankets, hot water bottles, warm IV fluids and a bear hugger (blanket with circulating warm air).
I referenced emedicine Hypothermia to answer this question.