Unusually hot weather in the Philippines was expected to last until mid-May, a forecaster said Sunday, after the temperature hit a record high in the capital Manila.

Extreme heat has scorched Southeast Asia in recent days, prompting thousands of schools to suspend in-person classes and authorities to issue health warnings.

In the Philippines, many people flocked to air-conditioned shopping malls and swimming pools for relief from the relentless heat.

"This is the hottest I've ever experienced here," said Nancy Bautista, 65, whose resort in Cavite province near Manila was fully booked due to the hot weather.

"Many of our guests are friends and families. They swim in the pool to fight the heat."

The temperature in Manila hit a record high of 38.8 degrees Celsius (101.8 degrees Fahrenheit) on Saturday with the heat index reaching 45C, data from the state weather forecaster showed.

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

The months of March, April and May are typically the hottest and driest time of the year, but this year's conditions have been exacerbated by the El Nino weather phenomenon.

"All places in the country, not necessarily just Metro Manila, are expected to have hotter temperatures until the second week of May," Glaiza Escullar of the state weather forecaster told AFP.

"There is a possibility that the areas will exceed those temperatures being measured today until the second week of May."

Camiling municipality in Tarlac province, north of Manila, recorded a temperature of 40.3C on Saturday -- the country's highest this year.

As the mercury rose, Gerise Reyes, 31, planned to take her two-year-old daughter to a shopping mall near Manila.

"It's hot here at home. This is the hottest I've ever experienced especially between 10:00 am and 4:00 pm," she said.

"We need a free aircon to cut our electricity bill."

Global temperatures hit record highs last year, and the United Nations' weather and climate agency said Tuesday that Asia was warming at a particularly rapid pace.

The Philippines ranks among the countries most vulnerable to the impacts of climate change.