TOP 3 THINGS YOU NEED TO KNOW ABOUT THE HEAT INDEX

As temperatures go higher and the weather gets warmer, we should be more prepared for the possible impacts of extreme heat. Part of being prepared is being aware and knowledgeable. Here are the top 3 things we, Filipinos, should know about the term heat index:

1. It’s how you feel.
Heat index, also known as human discomfort index, determines how your body perceives the temperature. Its two factors are air temperature and relative humidity.

Air temperature is what weather instruments measure, while relative humidity is the amount of moisture or water vapor in the air. It’s the reason why we get that “malagkit” feeling during hot days.

According to PAGASA Weather Forecaster Shelly Ignacio, a higher temperature and a high relative humidity will give a high heat index, making the body feels warmer.

The rate at which a person sweats depends on how much water is in the air. Sweat evaporates more quickly on dry days than humid days. On humid days, the air is saturated with moisture, resulting to a slower evaporation. A human body feels hotter in high humidity because sweat, the body’s natural cooling system, evaporates more slowly.

2. Heat index can be fatal.
In extreme cases, high heat indices can result to fatigue, heat cramps and heat stroke. If the heat index reaches 27 to 32 degrees Celsius, fatigue is possible, while prolonged exposure or activity can result to heat cramps.

Once heat index elevates to 32 to 41 degrees Celsius, extreme caution is needed due to possible heat cramps and heat exhaustion. The danger level begins when the heat index climbs to 41 to 54 degrees Celsius or more. In these cases, heat strokes, which are extremely hazardous, are more likely to occur.

The Department of Health (DOH) defines heat stroke as the most severe form of heat illness. This occurs when the body overheats and cannot cool down.

Signs and symptoms include warm flushed skin, feeling faint, dizziness, weakness, headache, high fever reaching 41 degrees Celsius, rapid heartbeat, convulsion, and sometimes, a patient may become unconscious.

To prevent heat stroke, take note of these tips:
– Stay indoors as much as possible.
– Wear lightweight and light-colored clothing. PAGASA explains that light colors will reflect the sun’s energy.
– Regularly drink plenty of water.
– Avoid drinking liquor because this dehydrates the body.
– Eat small but frequent meals. Avoid eating food with high protein content as these can increase metabolic heat.

3. Heat index is different from heat wave.
Some may think that heat wave and heat index are the same, but they’re not. Heat wave occurs when there is a prolonged period of extremely hot days.

PAGASA Weather Forecaster Meno Mendoza explains, “Mayroong sinusunod na criteria para dito, kailangan makapagtala tayo ng higit sa limang centigrade na above the normal na temperatura sa loob ng limang magkakasunod na araw (To declare a heat wave, we need to record a 5-degree increase in the normal temperature within 5 consecutive days.)” He added that heat wave has not yet occurred in Philippine history.

In related news, an intense heat wave is currently affecting the southern and eastern part of India. The death toll increased to more than 160. The Indian government are also concerned that more than 300 million people may be threatened by extreme drought and water shortage due to soaring temperatures. Last year, India’s heat wave claimed more than 2,000 lives.

Sources:
PAGASA-DOST
Department of Health
https://www.washingtonpost.com/news/worldviews/wp/2016/04/22/brutal-heat-wave-in-india-puts-330-million-people-at-risk/

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