The effect of temperature on the rate of oxygen consumption and heart rate has been investigated in the Red Sea, semi‐terrestrial crab,Ocypode saratan. The Q10values for both oxygen consumption and heart rate were often <2 and were relatively constant over a wide range of temperature. This suggests thatO. saratanis well adapted for life in a high temperature environment. It was noted, however, that behavioural mechanisms were important in reducing the degree of temperature stress that could be experienced in the field. The rates of oxygen consumption of immersed crabs were significantly lower than those of crabs maintained in air at the same temperature.