As the start of dry season in the Philippines has been declared officially, Filipinos should be mindful of their health amid the rising temperature to avoid heat-related illnesses.
According to the Philippine Atmospheric, Geophysical and Astronomical Services Administration, the heat felt by the human body or apparent temperature is not accurately measured using only air temperature. This is more accurately estimated if humidity or relative humidity data are included.
PAGASA said that this information is called the heat index and it can be determined using the heat index chart.
Air temperature differs from heat index as the latter is the measurement of how hot it feels when relative humidity is factored in with the actual air temperature.
Heat index is at least 3 degrees Celsius (°C) to 4°C higher than the actual air temperature.
However, PAGASA said that full exposure to sunshine can increase the heat index by 8 degrees Celsius.
From March to May, PAGASA provides heat index monitoring and forecast information that can be found on their website.
Effect on the body
PAGASA advised the public to observe “caution” when heat indices reach 27°C to 32°C as it may cause fatigue with prolonged exposure and activity, while continuing activity could lead to heat cramps.
With heat indices between 32°C and 41°C, PAGASA urged the public to observe “extreme caution,” as “heat cramps and heat exhaustion are possible,” and “continuing activity could cause heatstroke.”
Meanwhile, with heat indices between 41°C and 51°C, PAGASA said there is impending “danger as heat cramps and heat exhaustion are likely” and “heat stroke is probable with continued activity.”
If the heat index is over 52°C, PAGASA said there is “extreme danger” as “heatstroke is imminent.”
Heat stroke vs heat exhaustion
The US Centers for Disease Control and Prevention (CDC) defined heat stroke as “the most serious heat-related illness. It occurs when the body becomes unable to control its temperature: the body’s temperature rises rapidly, the sweating mechanism fails, and the body is unable to cool down.”
Heat exhaustion, meanwhile, “is the body’s response to an excessive loss of the water and salt, usually through excessive sweating.” People who are “most prone to heat exhaustion are those that are elderly, have high blood pressure, and those working in a hot environment,” the CDC said.
Symptoms associated with heat stroke include confusion, altered mental status, slurred speech; loss of consciousness; hot, dry skin or profuse sweating, seizures, and very high body temperature. For heat exhaustion, the usual symptoms are headache, nausea, dizziness, weakness, irritability, thirst, heavy sweating, elevated body temperature, and decreased urine output, the CDC said.
To avoid these medical problems, the public should always drink plenty of water, said infectious disease expert Dr. Edsel Salvana.
“Heat stroke is really the number one na nakikita natin and very important to stay hydrated and be aware of your surroundings. You can use like hats or umbrellas in some cases. But understand... nakakamatay po ang heat stroke . So it is very important to stay hydrated,” said Salvana in a recent press briefing.
Other ways to prevent these illnesses is to wear appropriate clothes such as those that are lightweight, light-colored, and loose-fitting, the CDC said.
If possible, an individual should stay cool indoors, the CDC said.
“Taking a cool shower or bath or moving to an air-conditioned place is a much better way to cool off. Use your stove and oven less to maintain a cooler temperature in your home,” it said.
“Try to limit your outdoor activity to when it’s coolest, like morning and evening hours. Rest often in shady areas so that your body has a chance to recover,” it added.
It also advised to “cut down on exercise during the heat.”
“If you’re not accustomed to working or exercising in a hot environment, start slowly and pick up the pace gradually. If exertion in the heat makes your heart pound and leaves you gasping for breath, stop all activity. Get into a cool area or into the shade, and rest, especially if you become lightheaded, confused, weak, or faint,” the CDC said.
People should also wear sunscreen to avoid sunburn.
“Sunburn affects your body’s ability to cool down and can make you dehydrated. If you must go outdoors, protect yourself from the sun by wearing a wide-brimmed hat, sunglasses, and by putting on sunscreen of SPF 15 or higher 30 minutes prior to going out. Continue to reapply it according to the package directions,” the CDC said. (With reports from Ellalyn De Vera-Ruiz)