To the Editor.—
Two letters published on febrile response to whirlpool bath treatments (238:1912, 1977; 239:1133, 1978) failed to mention the usual and expected response of patients to hot baths.Any person who is placed in a hot bath of 39 to 42 °C will manifest a febrile response corresponding to the temperature of the water and the length of time the person is kept in the bath. If an adult sits in a bathtub of hot water at about 42 °C, his oral temperature will usually rise in about 20 minutes to approximately 39 °C. A whirlpool bath can be used to administer fever treatments. I suspect this normal response to be the source of the febrile reactions Greenberg et al are reporting.