The number of people treated for heat-related illness in South Korea fell this summer from a year earlier, but estimated deaths rose. All of the increase in deaths occurred among people aged 80 and over, and the share of patients aged 65 and over also grew, prompting calls to widen the focus of heat-wave policy beyond outdoor worksites to the housing and care conditions of older adults.
A total of 4,066 heat illness cases were reported between May 15 and Sept. 30, down 394, or 8.8%, from 4,460 a year earlier, according to results of the 2026 emergency room surveillance system for heat-related illness released by the Korea Disease Control and Prevention Agency on the 12th. Estimated deaths from heat illness, by contrast, rose to 36 from 29, an increase of seven, or 24.1%.
The rise in deaths was concentrated among older adults. Estimated deaths among those aged 80 and over climbed 70% to 17 from 10 a year earlier. Deaths among those under 80 were unchanged at 19. People aged 80 and over accounted for 47.2% of the 36 estimated deaths. Broadening the range to those aged 60 and over, deaths totaled 28, or 77.8% of the total.
Older adults also made up a larger share of patients. Heat illness cases among those aged 65 and over rose to 1,421 from 1,341, lifting their share of all patients to 34.9% from 30.1%. By age group, people in their 60s accounted for the largest number at 773, or 19.0%. A year earlier, those in their 50s were the largest group at 865, but people in their 60s became the most affected age group this year.
The locations where cases occurred also shifted. Outdoor cases fell to 3,062 from 3,534, while indoor cases rose to 1,004 from 926. The indoor share climbed to 24.7% from 20.8%. Cases occurring at home jumped 48.9% to 353 from 237. Cases at outdoor worksites fell 25.9% to 1,060 from 1,431.
The risks of residential settings also stood out in fatalities. Estimated deaths occurring indoors doubled to 12 this year from six a year earlier. Of those, deaths at home rose to 10 from three. Deaths in fields rose to nine from five, and deaths on roadsides to eight from six. All 36 estimated deaths were attributed to heatstroke.
Heat illness was concentrated in early August. A total of 1,547 cases were reported from Aug. 1 to Aug. 10, or 38.0% of the total, while 16 estimated deaths during the same period accounted for 44.4% of the total. The average daily high temperature in that period was 34.4 degrees Celsius, 2.9 degrees higher than the same period last year.
By type of illness, heat exhaustion was the most common at 2,512 cases, or 61.8%. Heatstroke cases, however, rose to 704 from 667, and their share of all patients climbed to 17.3% from 15.0%.
The agency said that even though total cases declined this year, the increases in older patients, heatstroke and indoor cases mean the housing and care conditions of older adults need closer examination alongside existing prevention measures centered on outdoor activity and worksites. "Given that deaths among people aged 80 and over in particular have increased, we need to look closely at living environments and care conditions," KDCA Commissioner Lim Seung-kwan said. "It is important to reflect the identified characteristics of these cases in prevention measures."
