Protect Yourselves From Heatwaves

Throughout the globe, hot days are becoming hotter and more frequent. Climate change owing mainly to human activities has caused record-breaking heatwaves in almost every part of the globe. Our body has an extraordinary ability to cool itself as and when needed. It is usually fine when the ambient temperature is at or below the body temperature of 37°C. 

Our bodies attempt to keep a core temperature of about 37°C in all situations be it during a snowstorm or a heatwave. When our surroundings exceed the normal body temperature, the only way to keep from overheating is by sweating.  Heat causes more blood vessels open near to the skin so that heat is lost to our surroundings and starts sweating. As the sweat evaporates, it correspondingly causes heat loss from the skin.

Effects

The natural tendency of our body is to push sweat out onto the surface of the skin. As the air evaporates, it may take heat away from our bodies and cools us down. This mechanism of cooling works better in drier climates where humidity is low. Heatwaves become more dangerous particularly when combined with high humidity. In fact, humidity is a huge factor in terms of making the heat more severe to our bodies. When people are exposed to high temperatures and high humidity, they will be sweating but the sweat will not dry on the skin. Therefore, it is not just heat but the combination of heat and humidity that matters. People might become very tired and sometimes seriously ill if it doesn’t work quickly enough to cool the body.

Heat can affect anyone, however, some people are more at risk of serious consequences. People of old age or with some chronic illnesses such as heart disease can make them less capable to deal with the stress caused by heat on the body. People with diabetes may be at higher risk of heat effects. Diabetes makes the body loss water more quickly and the disease can alter blood vessels and the ability to sweat due to its complications. Children and those less mobile are also vulnerable to the effects of heat. The condition such as dementia, can also make people vulnerable to heat as they are unaware of the heat or unable to cope with it. 

Heat exhaustion is a body’s natural reaction to severe heat and can cause symptoms ranging from dizziness, headache to fainting. It can usually be treated at home with rest, a cool environment, and rehydration. Heatstroke is a severe situation when it is accompanied by dry skin, a body temperature above 103 degrees Fahrenheit, confusion, and sometimes unconsciousness and requires emergency medical attention. 

Very hot days with ambient air temperature more than our body temperature can lead to dehydration, heat exhaustion, and, in the worst cases, heatstroke. Heat exhaustion is not usually serious provided that a person can cool down within 30 minutes. It happens in extreme heat when our body cannot cool efficiently and sweats too much water and salt away leading to exhaustion with pale and clammy, and temperature often rises over 100 degrees. We should be cautious if it turns into heatstroke, emergency medical attention is urgently needed. 

As soon as the body gets hotter, blood vessels start dilating leading to lower blood pressure and making the heart work harder to push the blood around the body leading to mild symptoms such as a heat rash or swollen feet. At the same time, sweating leads to the loss of fluids and salt and, disturb mineral balance. If blood pressure decreases too far, the risk of heart attacks rises. Symptoms can range from dizziness, nausea, fainting, confusion, muscle cramps, headaches, and heavy sweating, to tiredness. 

In a very hot environment, excessive sweating causes the loss of essential minerals like sodium and potassium. We may be thirsty and urinate less than usual, and our mouth and tongue might feel dry. This situation even causes us to feel dizzy, lightheaded, and confused. It is, therefore, suggested to search for a cool place and drink fluids which are balanced with salt and sugar such as an oral rehydration solution.

Stay hydrated

Prevention is the key to dealing with very hot days and heatwaves. First and most important is to protect people who struggle to keep cool, such as older people, those with underlying chronic medical conditions such as heart disease, diabetes, dementia, etc., and those who live alone. 

It is advised to remain indoors by closing curtains in rooms that face the sun and drink copious amounts of fluids and avoid alcohol. It is particularly important not to go out during days when the sun’s rays are strong. If it is urgent to go outside, wear a hat or cap and sunglasses. It is suggested to drink regularly, but too much caffeine and sugar should be avoided. It is also important to eat small meals and eat more often but eat small amount of foods that are high in protein. It is also important to avoid physical exercise during day time and always carry water when traveling.

(Dr. Lohani is the clinical director at the Nepal Drug and Poison Information Centre. lohanis@gmail.com)