The Physical Environment:
The hot tub thermostat had been set at 102°F, although on the day prior and subsequently during the early morning, the County inspector had measured the actual tub temperature at 104°F. This event happened in mid-late afternoon, allowing solar gain to heat the hot tub well beyond 104°F. A systems engineer using finite element analysis estimated the tub temperature to be between 106°-109° F. on the day of the event. Using the same methodology, the temperature of the surrounding concrete was estimated at 139°F. As a consequence of the solar gain on both tub and concrete, this was a particularly dangerous environment for the risk of hyperthermia.