Effect of nembutal anaesthesia on the tolerance of high ambient temperature in guinea pigs.

A significantly lower rise of rectal temperature was observed in guinea pigs under nembutal general anaesthesia (2 degrees C) in comparison to the rise in this temperature in non-anaesthetised animals (2.6 degrees C) kept for 2.5 hours at an ambient temperature of 36 degrees C. Better tolerance of heat in the animals under general anaesthesia was due to reduced heat production and it was independent of a modification by nembutal of the thermoinsulating properties of the skin and coat, as it is a case at low and neutral ambient temperatures.