High temperature bathing in hot tubs, spas and whirlpools poses four potential public health concerns: injury/death, disease transmission, possible teratogenic effects, and congestive heart failure or dysrhythmias for individuals with cardiac problems. Health departments need criteria before initiating environmental and epidemiologic investigations. These criteria must include severity of the disease and number of individuals possibly exposed. In addition, public health officials are obligated to define the magnitude of the problem, inform affected individuals and institute appropriate control measures. Optional information should be collected during an environmental and epidemiologic investigation to clarify the mechanisms of disease transmission and design control measures. The public health response to improving hot water bathing safety and sanitation should be directed at primary prevention. Educational efforts would be directed toward whirlpool operators, users and the medical community. Included should be a review of regulations addressing the construction and operation of public spas and whirlpools.