South Korea has reported more than four-thousand heat-related illness cases this summer, already exceeding the total number recorded last year.

The Korea Disease Control and Prevention Agency said Monday 55 patients were treated in emergency rooms nationwide on Sunday for heat exhaustion and heatstroke, with one fatality.

That brought the cumulative number of patients since May 15 to four-thousand-48, with 26 deaths.

Although the traditional seasonal marker of Cheoseo on August 23 signals the retreat of summer heat, the toll has persisted, with one fatality reported on both August 23 and 24.

Officials attributed the surge to persistent heat waves, with daily maximum perceived temperatures topping 33 degrees Celsius in many regions.

The tally is now the second highest since records began in 2011, trailing only the record four-thousand-526 cases in 2018.