The first 1.5 mg/kg will be slowly injected in five equal doses (of 0.3 mg/kg) at 2 minute intervals during the last 10 minutes of cold water immersion. After removal from the water, further aliquots of 0.3 mg/kg (at minimum of 2-minute intervals) will be given only as necessary to inhibit any shivering that may develop, to a maximum cumulative dose of 3.2 mg/kg body weight.