The Navy SEAL Physical Fitness Guide - Uniformed Services ...

sure it is a cold environment when the ambient temperature is below 15° F and the windspeed is greater than 25 mph. Such environments pose potential dangers to those exposedfor any length of time.Factors that CompromiseAdaptations to Cold" Inadequate Energy Intake: Reduces the ability togenerate “metabolic” heat." Injury or Poor Physical Conditioning: Inhibits ability to generateheat through vigorous exercise." Dehydration: Places greater demands on the heart and speeds up fatigue." Low Percentage of Body Fat: Subcutaneous fat has insulating propertieswhich help protect against heat loss. This is a concern for SEALs, whousually have low body fat." Excessive Sweating: Dress appropriately using a layering systemand ventilate as necessary to avoid excessive sweating. Sweat willdestroy the insulating qualities of cold weather clothing and causeunwanted cooling by evaporation and freezing." Alcohol: Increases peripheral blood flow which promotes heat loss andcauses core temperature to fall more rapidly.Acclimation to the ColdUnlike acclimation to hot environments, there is little evidence to suggest that inhumans, there is a significant physiologic adaptation to the cold. There is evidence tosuggest that hands which are exposed to the cold for 30 minutes per day for three weekswill receive more blood flow and gradually become more “functional”. However, there isgreater heat loss through hands conditioned in this manner.Cold InjuriesThe spectrum of cold injuries experienced in the SEAL community is broad, but allcan be avoided by wearing appropriate clothing and paying attention for signs andsymptoms of cold injuries.The Navy SEAL Physical Fitness Guide 191