Physical and cognitive performance during long term cold weather operations
During extended cold weather operations, humans are subject to decrements of physical and cognitive performance. Performance has been shown to decline during short term and long term cold exposure. Previous studies have shown a decrement in muscle strength, dexterity, and complex mental tasks during short term cold exposure. Long term cold exposure studies have examined cognitive performance, but no physical performance or physiological parameters were measured. Studies were generally conducted in laboratory settings. A study was developed to examine the effects of extended cold weather operations on physical and cognitive performance, and physiological responses, where testing was conducted under field conditions. We studied five groups participating in nine-day cold weather survival courses offered by the Canadian Forces School of Survival and Aeromedical Training. Subjects (28 men) were instrumented for continuous field measurements of core temperature (T co) and heart rate. Finger tip temperature (Tfinger) was measured only at time of testing. Physical performance was evaluated with tests of strength (i.e. hand grip and upper body strength) and dexterity (i.e. lace-tying, nut-bolt, and a GPS entry test). Cognitive performance consisted of tests of logical reasoning, planning, and vigilance. Subjective scales of exertion, cold sensation, and mood were also used. Results indicated that hand grip strength (-12%) and dexterity [i.e. lace-tying (-31%), nut-bolt (-16%) and GPS] were detrimentally affected by cold. Cognitive tests showed no performance decrements.