#Health & Fitness

The Heat Is On: Physical Effects of Humidity

by Vicki Santillano

The Heat Is On: Physical Effects of Humidity

Image Credits: Haley Lawrence/Unsplash

I haven’t felt like myself all day today, and I think the weather’s to blame. It’s uncharacteristically muggy outside, which somehow makes my brain as frazzled as my hair.


What is it about humidity that pulls our bodies so forcefully out of whack? Heavy downpours and dry heat don’t seem to have the same startling effects. Sure, the former’s depressing and the latter’s tiring. But when excess moisture in the air combines with high temperatures, the results are far too overwhelming, at least for me. It makes me want to seek shelter indoors — and not just to hide my humidity-crazed hair from public view.


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I assumed my lethargy and frizzy hair in humid conditions were due to general weather weakness (which is also why I hate any temperature below sixty degrees) and bad hair genes. But it turns out that a high level of water vapor in the air does have physical effects on the body. And for some people with preexisting health conditions, it might actually be dangerous.


As it turns out, humidity has all sorts of effects on the body, ranging from frizzy hair to overall exhaustion. On warm days with high moisture levels, you may not feel quite like yourself — and that’s perfectly normal! Here’s why.


Does Humidity Affect Your Hair?


Humidity doesn’t dramatically change your hair texture — it just exaggerates what’s already there. For example, I have naturally curly hair, so on humid days my hair gets extra frizzy. And if my hair were super-straight, humidity would simply make it a little limper than usual.


Here’s the scientific explanation. Humidity affects hair’s temporary hydrogen bonds, which are what give hair styling flexibility (like the ability to straighten curly hair, for instance). On humid days, there’s much more water in the air than usual. This extra water causes the hydrogen bonds to break down and heightens the effects of permanent sulfur bonds (which are what creates hair’s natural texture). That’s the reason why when it’s humid, straight hair lies extra flat, while naturally curly hair takes on some extra frizz.


Translation: Yes, humidity affects your hair, making curly hair even curlier and straight hair even straighter.


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Does Humidity Make You Tired?


If you feel more tired when it’s humid outside, it’s not just you. Moisture-rich air makes the environment feel hotter than it actually is, which creates a sensation of exhaustion and fatigue. When the temperature is hot outside, your body must work much harder to maintain a comfortable internal temperature. Now you know why you might feel less productive at work on hot, humid days, or why your workout might feel more challenging than usual.


Humidity also interferes with sweating. The whole purpose of sweat in the first place is to release heat and cool off the body as the sweat evaporates from the skin. But when it’s humid, the air is so full of water that it’s unable to absorb moisture at the same rate or to the same extent. Since the sweat essentially has no place to go, your body becomes overheated. All these factors explain why you might feel weak, dizzy, or slightly confused on humid days. It’s not your mind playing tricks on you — it’s basic biology!


How Does Humidity Affect Overall Health?


Most people experience stubborn hair and sluggishness when the weather turns humid, but those are minor annoyances compared with the effects it can have on some people. Past research has linked high levels of water vapor in the air with increased symptom flare-ups in arthritis and rheumatoid arthritis sufferers, though the reason behind the supposed link is unknown.


A few studies have shown a correlation between humidity and asthma attacks as well. One in particular, performed at the University of Michigan and published in a 2009 issue of Annals of Allergy, Asthma, & Immunology, had particularly compelling results. Researchers reviewed two years’ worth of emergency room admissions at a Detroit children’s hospital. They found that when humidity went up at least 10 percent, there was a rise in asthma attacks. A few theories attempt to explain why this connection might exist — excess moisture makes the air heavier to breathe, for example — but more research is needed to come to a definitive conclusion.


Then there are the potentially life-threatening effects of overheating. When it’s humid, the body isn’t as efficient as releasing heat, which increases the likelihood of overheating, which can sometimes lead to heatstroke. The symptoms of heatstroke can be serious, including vomiting, muscle cramps, dizziness, headaches, a heightened pulse, and a sudden drop in blood pressure. If heatstroke goes untreated, it can even lead to organ damage, which is why consulting a doctor right away is of the utmost importance. Also noteworthy: People with compromised immune systems are higher risk for hyperthermia, as are the elderly, the very young, and the overweight.


But all in all, these are dramatic examples and a majority of people will be perfectly fine as the humidity cranks up.


How Do I Protect Myself From the Physical Effects of Humidity?


Evidently, the wear and tear humidity triggers isn’t all in our heads — it’s in our bodies, too. Make sure to take care of yourself when it’s extra humid out, watching for any possible symptoms of heatstroke and looking out for your loved ones, too.


Remember, don’t over-exercise, and make sure to have a water bottle ($17.95, amazon.com) on hand to remind yourself to drink plenty of water. It’s always important to stay hydrated, but on humid days, it’s especially crucial to make sure you’re getting plenty of H20 to mitigate humidity’s physical effects.


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If possible, seek shelter in an air-conditioned room; the Centers for Disease Control and Prevention say it’s the best way to protect ourselves from overheating and heat-related illnesses. If staying inside isn’t an option, you may want to grab a handheld fan ($11.99, amazon.com) and a bottle of sunscreen ($36, amazon.com) to keep you covered when you’re on the go.


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As for humidity’s aesthetic effects, there’s not much we can do about them. At least we can take comfort knowing that all the people around us are probably too busy worrying about their own hair situations to notice our own! Just throw on a hat ($15, amazon.com), gulp down some water, relax in a cool area, and hope for the best.


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