Manila (AFP): Dozens of schools in the Philippine capital of Manila suspended in-person classes on Tuesday due to dangerous levels of heat, education officials said.

The country's heat index measures what a temperature feels like, taking into account humidity.

The index was expected to reach the "danger" level of 42 degrees Celsius in the metropolis on Tuesday and 43C on Wednesday, the state weather forecaster said.

The actual highest temperature forecast for Manila on Tuesday was 34C.

Primary and secondary schools in Quezon, the most populous part of the city, were ordered to shut while schools in other areas were given the option by local officials to shift to remote learning.

Some schools shortened class hours to avoid the hottest part of the day.

A heat index of 42-51C can cause "heat cramps and heat exhaustion" with heat stroke "probable with continued exposure", the weather forecaster said in an advisory.

Heat cramps and heat exhaustion are also possible at 33-41C, according to the forecaster.