Abstract: A method of stunning an animal prior to slaughter involves heating at least a portion of the brain of an animal, using electromagnetic wave energy which penetrates the skull of the animal. The temperature of substantial portions of the brain is raised to a minimum of 41.degree. C in some cases and to higher temperatures in others. Heating of the brain is effected for a period of less than ten seconds and, preferably, for a period in the range of from 1 second to 7 seconds. The frequency of the electromagnetic wave energy is from 100 to 10,000 megacycles.