Dangerous heat index possible in 16 areas on May 5

State weather bureau PAGASA said that the heat index could reach the ''danger'' level in 16 locations on Sunday. 

These areas, based on PAGASA's forecast issued at 5 p.m. Saturday, are the following: 

48°C 
—Aparri, Cagayan 

47°C 
—Dagupan City, Pangasinan 

45°C 
—Virac (Synop), Catanduanes 

44°C 
—Laoag City, llocos Norte 
—Bacnotan, La Union 

43°C 
—Tuguegarao City, Cagayan 
—Masbate City, Masbate 

42°C 
—MMSU, Batac, Ilocos Norte 
—ISU Echague, Isabela 
—Casiguran, Aurora 
—Puerto Princesa City, Palawan 
—Cuyo, Palawan 
—Roxas City, Capiz 
—Dumangas, Iloilo 
—Zamboanga City, Zamboanga del Sur 
—Cotabato City, Maguindanao

PAGASA defines heat index as the measure of the temperature that a person feels, which is different from the actual air temperature. It is computed by factoring in the humidity and the air temperature.

In areas experiencing a danger level heat index, which is from 42°C to 51°C, heat cramps and heat exhaustion are likely, according to PAGASA. Heat stroke is also possible with continued exposure.

The Department of Health (DOH) reported on Saturday that the number of cases of heat-related illnesses this year has increased to 77.

Based on monitoring from January 1 to April 29, data from the DOH Event-based Surveillance and Reponse System showed that 87% or 67 of these cases were aged 12 to 21 years old. — VBL, GMA Integrated News