Due to climate change, late summer heat waves are getting longer, and the number of heat illnesses is increasing even after the autumnal equinox. From 2011 to 2015, the average annual number of heat illness patients who occurred from after the autumnal equinox to the end of August was 215, but from 2016 to 2020, it increased to about 3 times, 658 people. In particular, in 2024, 1,299 heat illness patients and 12 deaths occurred from after the autumnal equinox to the end of August, accounting for 35% of that year's total. Among the places where heat illnesses occurred, indoor and outdoor workplaces accounted for the highest proportion at 45.1%. It is expected that extreme heat will continue even after the autumnal equinox this year, so we need to pay more attention to preventing heat illness in vulnerable groups and indoor and outdoor workers.