Metro Manila experienced sweltering heat on Saturday as the temperature peaked to 36.2 Celcius with the heat index at 38.8, the hottest so far this year,

And no respite is in sight any time soon for residents reeling under the blistering heat as PAGASA warns Metro Manila’s heat index could reach up to 39 degrees Celsius come May.

Heat index refers to the temperature apparently felt by the body based not only on the air temperature but also on the humidity. It is often referred to as the human discomfort index.

According to PAGASA, a heat index of 32 to 41 degrees Celsius would require “extreme caution”. The danger threshold, the state weather bureau said, is when the heat index breaches 41 degrees.

When our body temperature reaches that point, we become susceptible to heat cramps and heat exhaustion. In worst case scenarios, continued activity could result to heat stroke.

Excessive heat spells danger

Excessive heat challenges our body’s ability to cool itself. When the body heats too quickly to cool itself properly, or when we lose too much fluid or salt due to dehydration or sweating, our body temperature peaks and that could result to heat-related illness.

Given the sizzling forecast in the coming days, it is crucial to know the symptoms of excessive heat exposure and the appropriate responses.

Here are the common heat-related illnesses and symptoms and the recommended first aid steps to take: