Temperatures are rising as the hot season settles in and health authorities are warning people to stay out of the sun if possible with the heat index having already hit the orange "dangerous to health" level.
The heat index for March 5-14 showed temperatures of 42-51.9ºC in some areas, which was considered dangerous to health. People in the southern, central, eastern and northeastern regions were all at risk, a top health official said.
People should check the weather forecast and avoid outdoor activities if possible, and drink water frequently, during hot weather, Thiti Sawangtham, deputy director-general of the Department of Health, said.
Heat rash, heat exhaustion and heat stroke could lead to death, Dr Thiti said.
The most sensitive groups were the elderly, the obese, outdoor workers and imbibers of alcohol, and people with underlying health conditions including mental issues, he said.
On Tuesday, the Meteorological Department reported 10 provinces where temperatures peaked at 38-39ºC on Monday, all in the North.
The upper part of Thailand would see cooler temperatures through to Saturday as cold air now covered parts of the Northeast. The forecast was for strong winds, but less rainfall, the report said.
The weather from March 23-28 would get hot to very hot again. There would be scattered summer storms, especially from March 29 into next month. However, this summer was not expected to be as hot as last year, it said.