Pasay City in Metro Manila and 15 other areas are set to experience dangerous heat index levels of 42 degrees Celsius and above this Friday, April 18, weather bureau PAGASA said.

Heat index is what the temperature feels like to the human body when relative humidity combines with air. 

Areas facing danger heat index levels are:

Pasay City

Aparri, Cagayan

Tuguegarao City, Cagayan

ISU Echague, Isabela

Baler, Aurora

Iba, Zambales

Cubi Pt, Subic Bay, Olongapo City

San Ildefonso, Bulacan

Sangley Point, Cavite City

Ambling, Tanauan, Batangas

Infanta, Quezon

San Jose, Occidental Mindoro

Roxas City, Capiz

Dumangas, Iloilo

Catarman, Northern Samar

Zamboanga City, Zamboanga del Sur

Heat cramps and heat exhaustion are likely in 42-51 degrees Celsius heat index range. Heat stroke is probable with continued exposure to such conditions.

Weather bureau PAGASA said Metro Manila and the rest of the country will experience partly cloudy to cloudy skies with isolated rainshowers or thunderstorms due to the easterlies.