The purpose of this study was to compare the thermoregulatory responses of trained paraplegics (TP) and able bodied subjects (AB) performing submaximal exercise of the same relative intensity in both hot and cool conditions. Five TP (lesion range T12 to L3) and five AB subjects experjenced in wheelchair use performed 60 minutes of constant load (55-60% of V02 max) arm ergometry exercise in 37°C and 15 °C climatic conditions. Heart rate (HR), sweat rate and rectal (Tr) and skin (fsk) temperatures were recorded. In the hot climate the TP subjects recorded a significantly greater change in fsk (�fsk) from 0 to 60 minutes of exercise than the AB subjects, because of greater thigh and calf temperatures, but no other significant differences were found between these groups. In the cool climate no significant differences were observed between the TP and AB groups. It was concluded that TP have a similar thermoregulatory ability to AB subjects who perform identical prolonged exercise in hot and cool conditions, although their lower limb skin temperatures are greater, probably because of venous pooling in the legs. While these results are a promising indication of the ability of TP to thermoregulate effectively while exercising in the, heat caution regarding their participation in endurance competitions in hot conditions should be expressed until data collected during wheelchair exercise (rather than arm ergometry) in the heat is available.