The Philippines authority on Monday cancelled in-person public school classes for the next two days.
This comes as the power grid on its main island could be strained as the country grapples with a heatwave that is also affecting other parts of Southeast Asia.
Sweltering heat in the Philippines can curb farm production, disrupt water and power and weigh on businesses, but it also takes a toll on students, Reuters reports.
Heat indices have hit 50 degrees Celsius (122 degrees Fahrenheit) in various regions in the Philippines, as the weather phenomenon El Nino intensifies the heat enveloping the nation in its summer months of March to May.
The Philippines scores among the lowest in the world in math, science and reading, partly because of years of inadequate remote learning during the pandemic, according to the Programme for International Student Assessment, an international study of education systems.
The state weather agency on Monday forecast temperatures in the capital region could reach 37 degrees Celsius (98.6 degrees Fahrenheit) in the next three days.
Reuters reports that the agency said the heat index -the actual temperature felt by the body to include relative humidity - is expected to remain at a record 45 degrees Celsius (113° Fahrenheit), in the range which it classes as "dangerous" as conditions can trigger heat stroke from prolonged exposure.
The heat index could continue hitting record highs until the second week of May, Glaiza Escullar, a state weather forecaster, told DZBB radio station.
The heatwave is putting pressure on power supplies on the main island of Luzon, which accounts for three-quarters of economic output, with reserves thinning after 13 power plants had shut down earlier this month, the Philippines' grid operator said in a statement.
In Indonesia, warmer temperatures have been cited as a factor in a surge in cases of dengue fever, a mosquito-borne infection, to 35,000 cases last month from 15,000 a year earlier.
The Philippines' education ministry on Sunday ordered public schools to shift to online learning due to the record heat index forecast, as classrooms can be crowded and most do not have air-conditioning.