Effect of alcohol on thermal balance of man in cold water

Abstract

The effects of alcohol on core cooling rates (rectal and tympanic), skin temperatures, and metabolic rate were determined for 10 subjects rendered hypothermic by immersion for 45 min in 10 degrees C water. Experiments were duplicated with and without a 20-min period of exercise at the beginning of cold water immersion. Measurements were continued during rewarming in a hot bath. With blood alcohol concentrations averaging 82 mg 100 mL-1, core cooling rates and changes in skin temperatures were insignificantly different from controls, even if the exercise period was imposed. Alcohol reduced shivering metabolic rate by an overall mean of 13%, insufficient to affect cooling rate. Alcohol had no effect on metabolic rate during exercise. During rewarming by hot bath, the amount of 'afterdrop' and rate of increase in core temperature were unaffected by alcohol. It was concluded that alcohol in a moderate dosage does not influence the rate of progress into hypothermia or subsequent, efficient rewarming. This emphasizes that the high incidence of alcohol involvement in water-related fatalities is due to alcohol potentiation of accidents rather than any direct effects on cold water survival, although very high doses of alcohol leading to unconsciousness would increase rate of progress into hypothermia.

National Athletic Trainers' Association Position Statement: Environmental Cold Injuries

“…As with alcohol, they may also lead to faulty decision making. 77,81,82 Body Size and Composition. Body fat and muscle mass appear to be instrumental in providing protection for maintaining core body temperature with exposure to cold air and water.…”

Response to Thermal Stress in the Rat following Acute Administration of Ethanol

“…3). Similarly, no increase was noted in Tsk of the rat at Ta 18-26 °C following acute administration of 1-1.5 g ethanol/kg [22,23], Recent studies in humans, also show no increase in heat loss following acute administration of ethanol and exposure to either thermoneutral [20] or cold Ta [2,9,16,19]. Thus, it seems unlikely that the decrease in Tco in the mammal fol lowing acute administration of 3 g ethanol/kg is due to an increase in peripheral heat loss.…”

“…Early investigators noted an increase in peripheral vasodilation and suggested an increase in heat loss accompanied acute ad ministration of ethanol [5,12,13,17,36], However, a number of other reports indicates that there is little change in total body heat loss from man following intake of ethanol at either cold [2,9,14,25] or neutral Ta [20].…”

Comparison of Heat Donation Through the Head or Torso on Mild Hypothermia Rewarming

“…Several studies have also shown that moderate doses of alcohol (blood alcohol levels of 50-100 mg/dL) can affect the thermoregulation during a cold exposure (17,45,54).…”

“…However, in colder water (<28˚C), it has been shown to reduce the metabolic heat production by 10-20% with no significant increase in the core cooling rate (17,54).…”