Board Review: Hypothermia/Cold Water Submersion

Author: Kevin P. Beres, DO PGY-1
UTHealth Emergency Medicine Resident

Originally Published: Modern Resident, April/May 2015 

Growing up in Wisconsin, one of the beloved New Year’s traditions was the polar bear plunge, which translates to a group of people jumping into the cold lakes on New Year’s Day. This event brings up two important concepts: cold water submersion and accidental hypothermia. Risk factors for accidental hypothermia include alcohol, AMS, behavior, extreme ages and certain comorbidities including peripheral vascular disease, trauma and diabetes mellitus.[1,2]

Cold Water Submersion:
When the body comes into contact with cold water, it leads to activation of the Mammalian diving reflex, resulting in bradycardia, shunting of blood to the CNS system and slow metabolism and may actually prolong survival.[1] This reflex affects children more efficiently than adults. Alcohol has been shown to reduce this reflex.[3]

Chilblains:
Chilblains are red and/or blue edematous plaques and papules that appear on the distal extremities that occur secondary to prolonged cold exposure. A variety of sensory symptoms such as itching or burning can accompany the skin changes.[1]