ALCOHOL INGESTION AND TEMPERATURE REGULATION DURING COLD-EXPOSURE

Outdoor or wilderness activities are sometimes combined with the inges tion of alcoholic beverages. Despite the feeling of warmth induced by alcohol ingestion, it is widely believed that alcohol actually causes a decrease in body core temperature and increases the risk of hypother mia during cold exposure. However, the literature on the effects of al cohol ingestion on thermoregulation is conflicting. This review summar izes the scientific findings concerning this topic and identifies a nu mber of confounding factors that may explain the conflicting observati ons. These factors include quantity of alcohol ingested, severity of t he cold stress, nutritional state of the individual, composition of th e drink, body composition of the individual and alcohol tolerance of t he individual. When these factors are considered, it appears that (1) alcohol acts as a poikilothermic agent, causing a reduction in body co re temperature during cold exposure, with the magnitude of reduction r elated to blood alcohol concentration, (2) the severity of cold and th e individual's body composition modify the thermoregulatory effects of alcohol, and (3) hypoglycemia greatly exacerbates the reduction in bo dy temperature caused by alcohol ingestion. Furthermore, the primary m echanism by which alcohol ingestion exacerbates the fall in body core temperature during cold exposure appears to be via an impairment of sh ivering thermogenesis resulting from alcohol-induced hypoglycemia, rat her than by increasing heat dissipation via vasodilation as commonly b elieved.