Do you think you have heard enough about heat? Are you tired of hearing about how hot it is all over the world? Do you believe this heat problem is just a passing phase and that you already know enough about heat, or as much as you are ever going to need to know? Still don’t think climate change is real? Then trust me, you don’t know enough about heat! If you don’t want to trust me on this, please at least humor me and read this article. It sure feels great in the wintertime to come into a heated house from the freezing cold, doesn’t it? And we sure love going to the beach on a hot day to get outdoors, relax, maybe jump into the water and swim, lie on the beach, get a suntan. But things are different now with climate change. The summers of 2022 and 2023 were brutal. Many people died from the heat. Why is that? Let’s first look at the effects of heat on the human body. Historically, humans have been able to acclimate to changes over longer periods of time. But what scientists are seeing now are significant temperature changes happening very quickly, and they are beginning to worry about the heat stress tolerance of humans.
Staying cool
As we know from all the doctor visits in our lives, our bodies have ways to shed excess heat and keep an optimal core temperature of 98.6 Fahrenheit. In general, our bodies must have a core temperature between 97- and 99-degrees Fahrenheit to protect our organs. Humans get rid of built-up body by evaporation of sweat. When we get hot, our heart pumps faster and we sweat. With a faster heart rate and blood flow, the body carries heat to the skin where the core heat can evaporate into the air and help cool our bodies. But when the heart must work harder, infants, the elderly, and people already suffering from heart conditions or sicknesses may be particularly vulnerable to heat exhaustion or heatstroke, when their core body temperature rises. Also, the more humid it is, the less sweat we produce to evaporate and cool our bodies.
What happens inside our bodies when it is very hot?
Heat stress happens when the body builds up more heat than it can release. We already know the heart is pumping faster to get more blood flowing to the skin so that more heat can be released from our bodies. But if there is a lot more blood flowing toward the skin, some parts of our body are going to get less blood flow. The body also needs to take in more oxygen and limit the muscles from producing heat, so we breathe harder, and our bodies move more slowly. We can lose a lot of fluids through heavy sweating and become dehydrated. Even worse, we can cause damage to our kidneys and our gastrointestinal tracts if blood flow to these organs continues for long periods of time. The most dangerous result of exposure to heat is heatstroke. This is when body temperature is 103F or higher, and your brain, kidneys, heart, and gut can become damaged. People may experience confusion, hallucinate, have seizures, or even go into cardiac arrest. Heatstroke is a medical emergency where the most critical response is to immediately cool the body anyway you possibly can (water, ice, air-conditioning, shade), whatever is available, and call an ambulance or find help. It is critical to get the body temperature down fast. The longer the body remains at the higher temperatures, the greater the chances of severe damage.
So, what we should be doing?
We hear it all the time, and a lot of what we hear is common sense, but if you are out in the heat and you get muscle cramps, feel dizzy, lightheaded, are having headaches, or feel like you are going to faint, you may be experiencing heat exhaustion where your body is not getting rid of enough heat. You must stop what you are doing, get out of the heat, and get hydrated. This is especially true if you work outdoors. You MUST take regular breaks in the shade and stay hydrated. Some states are looking into laws that would make shade and water breaks mandatory for agricultural and construction workers, and jobs requiring workers to be outside in the heat for long periods of time. The same precautions apply to strenuous exercise or activities outside. The National Weather Service has shown that heat is one of the top weather killers in the United States. Next time we will get into more facts and figures about heat.
Sources:
https://www.sciencenews.org/article/heat-humans-stress-extreme-climate-change-physiology
C. Raymond, T. Matthews and R.M. Horton. The emergence of heat and humidity too severe for human tolerance. Science Advances. Published online May 8, 2020. doi:10.1126/sciadv.aaw1838.
https://www.simplemost.com/how-much-heat-is-too-much-human-body/
https://www.theguardian.com/us-news/2023/aug/17/heat-stress-heatstroke-temperatures
