Two mountain areas of Chocolate Hills in the municipality of Carmen in Bohol were razed as a grassfire incident occurred on Tuesday night.

Dr. Anthony Damalerio, head of the Bohol Provincial Disaster Risk Reduction Management Office (DRRMO), said that the fire started at 7:30 p.m. and was declared fire out by the Bureau of Fire Protection (BFP) at 10:35 p.m.

According to him, the fire was caused by the extreme heat.

"Spontaneous combustion is the report of the BFP, probably due to the extreme heat; too high heat index felt not just in Bohol but to the entire Visayas," he said in a radio interview on Wednesday.

Damalerio further said that several cases of fire incidents in their area have been recovered, even at night.

"A week ago, there was also the municipality of Sierra Bullones, just next to Carmen. Same as the grass fire incident," he said.

The provincial DRRMO officer said that the BFP concentrated their response at the base of the mountain so that the fire would not spread to other mountains.

"That's the response of the BFP. They could not climb the tip of the mountain, so they controlled the adjacent mountain areas of Chocolate Hills," he added.

The latest forecast of the state weather bureau PAGASA shows that a heat index of 41°C is predicted at the province's Panglao International Airport.

Also called the 'init factor', the heat index is the human discomfort index that gives the "apparent" temperature, or what humans perceive or feel as the temperature affecting their body.