While the buffalo is remarkably versatile, it has less physiological adaptation to extremes of heat and cold than the various breeds of cattle. Body temperatures of buffaloes are actually lower than those of cattle, but buffalo skin is usually black and heat absorbent and only sparsely protected by hair. Also, buffalo skin has one-sixth the density of sweat glands that cattle skin has, so buffaloes dissipate heat poorly by sweating. If worked or driven excessively in the hot sun, a buffalo's body temperature, pulse rate, respiration rate, and general discomfort increase more quickly than those of cattle(Failure to appreciate this has caused many buffalo deaths in northern Australia when the animals were herded long distances through the heat of the day as if they were cattle).. This is particularly true of young calves and pregnant females. During one trial in Egypt 2 hours' exposure to sun caused temperatures of buffalo to rise 1.3°C, whereas temperatures of cattle rose only 0.2-0.3°C.Buffaloes prefer to cool off in a wallow rather than seek shade. They may wallow for up to 5 hours a day when temperatures and humidity are high. Immersed in water or mud, chewing with half-closed eyes, buffaloes are a picture of bliss.In shade or in a wallow buffaloes cool off quickly, perhaps because a black skin rich in blood vessels conducts and radiates heat efficiently (Tests at the University of Florida have shown that buffaloes in the shade cool off more quickly than cattle. .Nonetheless, wallowing is not essential. Experience in Australia, Trinidad, Florida, Malaysia, and elsewhere has shown that buffaloes grow normally without wallowing as long as adequate shade is available.