Prolonged immersion in hot water may induce hyperthermia.
The use of alcohol or drugs can greatly increase the risk of fatal hyperthermia in hot tubs or spas.
Hyperthermia occurs when the internal temperature of the body reaches a level several degrees above the normal body temperature of 99ºF (37°C). The symptoms of hyperthermia include drowsiness, lethargy, and an increase in the internal temperature of the body. The effects of hyperthermia include:
- Unawareness of impending hazard;
- Failure to perceive heat;
- Failure to recognize the need to exit hot tub;
- Physical inability to exit hot tub;
- Fetal damage in pregnant women; and
- Unconsciousness and danger of drowning.