THE weather agency on Monday advised the public to stay indoors as it warned that the heat index in Metro Manila may reach 39 to 41 degrees Celsius until the weekend.

“We are advising the public especially in Metro Manila to exercise extreme caution and better stay indoors and stay hydrated,” weather forecaster Grace Castañeda said.

She added that the heat index on Monday, May 17, 2021, may hit 38 degrees Celsius.

The Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) defines heat index as the apparent temperature felt by the body.

Castañeda urged those who have to go outside to stay in the shade and frequently drink water.

She said exposure to extreme heat may result in heat cramps and exhaustion that may lead to heat stroke.

“Drink plenty of water regularly as our body needs water to keep cool. Water is the safest liquid to drink during heat emergencies,” Pagasa said.

“Avoid drinking liquor because it dehydrates the body,” it added.