The effects of heat stress on an individual's static work capabilities were investigated. Various indicators of strength and endurance were measured under differing heat stress levels. One measure which exhibited a significant change at higher heat stress levels was a combined strength-endurance measurement involving a series of maximal voluntary contractions throughout a one hour exposure. At 35° C WBGT the decrease in MVC from the beginning of the exposure to the end was 43% compared to only 6% at 18° C WBGT. Core temperature was also monitored throughout each exposure.