The impact of a heat wave on body temperature of patients being admitted to the emergency department (ED) and of patients that were already hospitalized was investigated. This can provide insight into measures or infrastructural adjustments that still need to be made.

A retrospective study comparing the measured body temperature of patients admitted to the ED and patients already hospitalized during a heat wave from August 11-13, 2020 versus a period in which no heat wave, no manifest presence of COVID-19, and no other endemism was present (October 10 and October 20, 2019, and November 5, 2019) was conducted. Two groups were created per period: morning and afternoon measurements.

Comparing the heat wave to the control period, no statistical difference was observed in morning temperature measurements at the ED. In the afternoon temperature measurements at the ED, however, a statistically significant difference (p < 0.01) was measured. Afternoon measurements during the control period showed a mean of 36.842 °C, whereas the measurements during the heat wave showed a mean body temperature of 37.191 °C. For hospitalized patients, a statistical difference (p < 0.01) was measured in both morning and afternoon temperature measurements. The control period showed a mean morning body temperature of 36.629 °C and a mean afternoon body temperature of 36.7154 °C, as opposed to the heat wave mean body temperatures in the morning (36.698 °C) and afternoon (36.7937 °C).

This study emphasizes the rise in body temperature during a heat wave, independently of other factors that influence body temperature. Hospitals should focus on preventive measures, such as air conditioning and providing good temperature control. Further research is needed.