Heatwaves and Heat-related Conditions | All you Need to Know

Prolonged heatwaves lead to more heat-related illnesses. Learn everything you need to know about these medical conditions in this guide.

Heatwaves and Heat-related Conditions | All you Need to Know
Reviewed by Dr. David Zlotnick, Chief Medical Officer at Antidote Health

The Earth is getting warmer. And even though we are aware of the dangers of global warming, they very rarely become the thing that everybody talks about. This collective apathy, or inability to motivate people to address climate issues, stems from a number of different reasons, one of which is that climate change is portrayed as “tomorrow’s problem.” There is a sense that we don’t feel the full effects of climate change, and have other, more urgent worries to take care of first. But that’s false. The rise in temperatures causes more frequent and intense heatwaves, and those can have dire consequences on our lives today. What are the most common heat-related illnesses, what are the signs you should be aware of, and how can you help others who are suffering? Learn everything you need to know about heat-related medical conditions in this guide. 

Perhaps the most intuitive consequence of global warming is rising temperatures. Since the 80’s, each decade has been warmer than the decade before, and there is no reason to assume that the trend is going to change. In fact, the two warmest years to ever be recorded – 2020 and 2016 – were recorded in the past decade. This temperature increase is a precursor to heat-waves, generally defined as a series of unusually hot and humid days. Heatwaves occur more often than they used to, they last longer, and are more intense. Naturally, heatwaves have been linked to different kinds of heat-related illnesses. 

What are heat-related illnesses? 

Heat-related conditions occur when our internal temperature control system is overloaded. A part of the brain called the hypothalamus constantly regulates our temperature, and works to keep it within a degree or two of 98.6°F. It helps us cool down by evaporating water and salts when we are too hot (also known as sweating), and generates heat when our body temperature gets too cold. 

Our internal temperature is affected by both internal (i.e. your body fighting bacteria causing fever) and external factors. Heatwaves are comprised of heat and humidity. Intense heat causes the body to sweat so much it drains the body of fluids and salts, and water in the air makes it harder for our sweat to evaporate and cool down our body. In some cases, body temperature rises so quickly that sweating simply isn’t enough. This external factor may lead to various health concerns in anyone, but more severely affects those who have a problem regulating temperature, such as people 65 and older, children under 4, people with obesity, and people with underlying conditions or on certain medications. 

What are common heat-related medical conditions? 

There are different kinds of heat-related medical conditions, ranging from mild to severe. Three of the most common are: 

Heat Edema (swelling):

It is pretty common for legs, ankles, and hands to swell when we stand or sit in hot weather. This phenomenon, called heat edema, is caused by blood moving into our limbs due to gravity. Why does it happen when it’s hot? The swelling is essentially a side-effect of the expansion of our blood vessels, an essential (and normal) way for the body to regulate temperature and cool itself down. Swelling is also linked to higher than normal levels of salt in the body, which can draw fluid to our ankles, hands, and legs. 

The best way to treat heat edema is to prevent the blood from ever settling in the limbs. Try to stay away from hot temperatures for long periods as much as possible, avoid salt, drink a lot of water, and move regularly. If, for example, your feet are already swollen, simply elevate them. (If your boss walks in to see you sitting with both legs on the desk, share this article with them). If that doesn’t solve the problem, contact Antidote Health’s certified clinicians, as it might suggest a more serious problem with your veins and further testing is advised.

Heat Rash (prickly heat, miliaria):

Heat rash is often associated with infants, but can appear in adults as well, especially during heatwaves. Heat rash usually occurs when sweat glands are blocked and sweat cannot leave the body and evaporate. This leads to bumps, mild swelling, and skin irritation that can spread in the body (but not infect others). Heat rash is linked to excessive sweating, which naturally happens during a heatwave. (Excessive sweating also occurs during exercise, making heat rash one of the only conditions for which physical activity is a risk factor!).

Apart from the aggravating feeling, heat rash is usually harmless and goes away on its own. If you’re experiencing prickly heat, try to keep your skin cool – don’t sweat and irritate the skin. Things you can do to ease the symptoms include taking cool showers, avoiding the sun, drinking a lot, wearing loose clothing, and avoiding perfumed shower gels and creams. If the rash doesn’t get better after a few days, you should contact a health professional. 

Heat Cramps:

When we sweat, we release water and salt. People who sweat a lot and exhaust the levels of salt in their body might experience painful spasms. These cramps are usually more intense and prolonged than the common leg cramps you might feel at night. Most people will feel the cramps in their arms, legs, and abdomen. Similar to heat rash, physical activity in hot weather is also a risk factor for heat cramps. 

As soon as you feel cramps, stop your activity, sit down in a cool place, and drink juice or a sports drink to restore salts and minerals to your body. Whatever you do – do not keep exercising through the pain. Let your body rest and the cramps subside. Pushing through may lead to heat exhaustion or heat stroke. If you have heart problems or are on a low-sodium diet, or if heat cramps don’t ease within an hour, reach out to a medical professional.

Heat exhaustion vs. heat stroke: what are the symptoms and differences between them? 

As noted above, some heat-related conditions will usually resolve themselves with basic self-care. Heat exhaustion, if not treated immediately, or you don’t cool down within 30 minutes, can turn into heat stroke, the most severe heat-related medical condition. If you suspect someone is suffering from heat exhaustion, seek medical attention immediately.

The symptoms of heat exhaustion are: 

  • Heavy sweating 
  • Cold and pale skin
  • Fast and weak pulse 
  • Nausea or vomiting 
  • Overall weakness 
  • Headache, dizziness, and confusion
  • Passing out 
  • Loss of appetite and feeling sick

If someone around you is having any of these symptoms, there are four steps you should take immediately: 

  1. Move them to a cool place
  2. Lay them down and raise their legs slightly
  3. Give them something to drink (water is ideal, sports drinks are acceptable too, but definitely avoid alcohol)
  4. Cool their skin in any way possible

Stay with them until they feel better. If they don’t seem to get better within 30 minutes, call 911.

When heat exhaustion turns into heat stroke: 

Heat stroke happens when the body is unable to control its temperature and cool down. You can tell that a person is experiencing heat stroke, and not heat exhaustion, by a rapidly rising body temperature, a lack of sweat, and a strong and quick pulse, in addition to heat exhaustion symptoms. 

Without immediate care, heat stroke can be fatal. If you have the slightest concern that you are witnessing a person showing signs of heat stroke, call for immediate medical assistance while performing the four cooling-down stages mentioned above. 

As in many other cases, prevention is the best way to stay healthy. It is better to help your body regulate temperature in hot weather than to treat heat-related illnesses. Drink more water than you think you should, take cool showers, wear light and loose clothes, avoid being outside when the sun is beaming, apply sunscreen, avoid alcohol, try to exercise with a friend, and keep an eye on your surroundings as some people – especially the elderly – might need your help. Lastly, you should be aware that cities across the country have repurposed libraries and other public facilities and turned them into cooling centers for anyone to use. If you have to be outside during a heatwave, search for cooling centers around you so that you know where you can stop for an air-conditioned break. Unfortunately, with the warming of our planet and the rise in heatwaves in the U.S. and across the world, we are likely to see an even greater increase in heat-related medical conditions in the future. Knowing what to look for in yourself and others and what to do in case of an emergency can save lives.

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