A total of 21 patients suffering from heat-related illnesses were reported on Wednesday alone as the nation experienced unusually hot weather for the month of May. 

The Korea Disease Control and Prevention Agency (KDCA) disclosed the figure on Thursday, saying that the cumulative number of such cases this year has climbed to 44 since it began operating a monitoring system last Thursday. 

Of the 21 cases reported on Wednesday, seven came from Gyeonggi Province. 

No deaths from such illnesses were reported and male patients made up more than three out of four of total cases.