The heat wave killed at least 15 people in Japan during the first two weeks of July while 12,000 people were hospitalized, according to official figures released Sunday when the thermometer was nearly 40 degrees Celsius in many cities.

Twelve people died in the week ended July 15, for more than 9900 hospitalizations, three people died the previous week, for 200 hospitalizations, according to the disaster management agency.

But it was not time for refreshment.

According to Kyodo News, at least 11 people died on Saturday alone, mostly for the elderly.

The meteorological agency announced that temperatures exceeded Sunday afternoon the 35 degrees in 233 points of the archipelago. In Gugo, central Japan, it was 39.8 degrees and in several areas of Tokyo, the thermometer exceeded 37 degrees.

The agency has issued a hot warning for most areas of the main island of the archipelago. “The risk of heat stroke is particularly high,” she said, calling people to drink a lot and use air conditioning.

The Ministry of Education has asked schools to give up outdoor activities during hot weather. A six-year-old boy died last week of heat stroke during a school trip.