Proportion of Heat-Related Illnesses at Home Doubles During Extreme Heatwaves

▲ Heatwave

The proportion of heat-related illnesses occurring at home has been found to more than double during extreme heatwaves when daily high temperatures reach 38 degrees Celsius or higher.

According to the Ministry of the Interior and Safety, the vast majority of heat-related illnesses in South Korea occur outdoors, such as at outdoor workplaces, fields, and roadsides, while the proportion occurring at home typically remains around 6 percent, which is relatively low compared to other countries.

However, an analysis of data from the Korea Disease Control and Prevention Agency and the Korea Meteorological Administration by the National Disaster Management Research Institute from 2011 to 2025 revealed that during extreme heatwave situations where daily highs soar to 38 degrees Celsius or higher, the proportion of heat-related illnesses occurring at home rises from the usual 6 percent to about 12 percent, roughly a twofold increase.

This trend was also observed in France and Japan, which suffered heavily from extreme heat damage this year.

France experienced its hottest June heatwave on record this summer, with the nationwide daily average temperature reaching 30 degrees Celsius (peaking at 44.3 degrees Celsius) and the highest-level red heatwave alert issued across 72 administrative regions.

As a result, during this heatwave period (June 17 – July 2), excess deaths were 5,764 (36.2%) higher than the same period in typical years, and during the peak week of the heatwave (June 22 – 28), deaths at home surged by 91% compared to the previous week.

Realizing that it is more difficult to protect vulnerable people isolated at home than those in nursing facilities, the French government focused on outreach protection to check on people isolated at residences.

In Japan, temperatures hit 40 degrees Celsius or higher for five consecutive days from July 21 to 25, resulting in 18,591 emergency transports for heat-related illnesses during just one week at the peak of the heatwave, with the most common location of occurrence being homes (40.9%) rather than workplaces or roadsides.

In particular, an investigation into the circumstances of 35 heat-related deaths in Tokyo revealed that 74% (26 people) either did not have air conditioners installed or had units that were not working.

In response, the Japanese government urged people to properly use air conditioning, including at night, and designated 1,255 basic local government jurisdictions as cooling shelters to cope with the situation.

Minister of the Interior and Safety Yoon Ho-jung stated, "While South Korea does not have a high proportion of heat-related illnesses occurring within residences compared to other countries, patients occurring inside homes tend to increase as heatwaves become more severe."

He added, "When the heat is severe, please actively use cooling appliances to maintain appropriate indoor temperatures day and night. If cooling is difficult, we hope you will check the locations and operating hours of nearby cooling shelters in advance and make active use of them during heatwaves."

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