By Debi Solberg RN CCRN, ALNW Flight Nurse Hypothermia is a physiological condition in which the human body temperature falls below 35 degrees Celsius, and is a condition pre-hospital providers must frequently address in the Pacific Northwest. What may begin as a warm, sunny day may deteriorate into a life-threatening situation if the weather should suddenly turn cool and wet. When sufficient heat cannot be generated to maintain temperature homeostasis and the body core drops to below 30 C, the patient will cool to the ambient external temperature. The potential for hypothermia exists whenever heat loss exceeds heat production and conservation.
Body heat is produced by metabolic activity and shivering.
Shivering, an automatic body response to cold that is intended to move muscles and produce heat, will increase O2 consumption and metabolic demands which can further compromise the exposed individual. Alcohol and many drugs promote hypothermia by producing sedation and inhibiting shivering. Thus, the human body responds to cold by first raising the blood pressure and heart rate. After the initial tachycardia, which also increases myocardial O2 consumption, bradycardia follows. As the cooling continues, confusion and mental depression slowly set in.