The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said that San Ildefonso in Bulacan province is expected to register the highest heat index on Saturday, possibly reaching 41 degrees Celsius — a level that requires heightened awareness of heat‑related health risks.
Across the country, 66 areas have been placed under an “extreme caution” heat index warning, indicating that conditions could cause heat exhaustion and other heat‑induced illnesses with prolonged exposure. The “extreme caution” category typically involves heat index readings where the combined effects of temperature and humidity make it feel significantly hotter than the actual air temperature.
PAGASA’s heat index advisories are based on the perceived temperature — how hot the conditions feel to the human body when humidity is factored in — and are designed to help local authorities and the public prepare for potentially dangerous weather conditions. This classification comes as part of routine monitoring, especially toward the peak of the dry season.
Health experts remind the public to take precautions during extreme heat, such as staying hydrated, avoiding strenuous activity during midday, and remaining in shaded or air‑conditioned areas as much as possible to reduce the risk of heat‑related illnesses.