Due to the heatwave in Japan, the number of patients with heatstroke transported via ambulance hit the highest record according to the Tokyo fire department in 2018. Now, heatwaves are thought to be a natural disaster. Emergency medical professionals located in a Tokyo suburb covering 40,000 individuals experienced a wide range of challenges in patient care with heatstroke.

To assess the impact of the 2018 Japan heatwave on community emergency medical service.

Patients (aged ≥ 16 years) with heatstroke and who were transported to our hospital by ambulance from June to September of 2018 were included. Data were derived from prehospital records and electronic medical records. Weather data was referenced from a Japanese meteorological agency.

The number of all-cause cases was 1,764, and the total number of heatstroke cases was 51 (2.9%). Heatstroke cases were concentrated in July and August of 2018. The rate of males was 69%. The average age was 63 ± 23 years. Physical labor was associated with 31% of cases, such as sports in 7.8%. Hospitalization was required in 24%. ICU admission was required in 9.8%. There was no fetal case directly caused by heatstroke in this survey.

The risk factors of heatstroke considered to be male and elderly. About one-half of heatstroke patients were over 70 years old, and it may have been related to regional characteristics. As mentioned in the Heatstroke STUDY 2012 (Miyake, 2014), most cases which occurred inside residences were found that there was no air conditioner use. There was also an increased number of patients with heatstroke who made emergency visits by themselves. Further investigation is needed annually to estimate the effect of climate change. It is important to make a strong recommendation from public health agency about heatstroke prevention, including air conditioner use during hot weather.