Roasting in April: A Beat-the-Heat Offensive

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ImpactWeather Meteorologist Andrew Artzer was home visiting his parents last week in Kansas. Ever the geeky meteorologist (his words, not mine), he recapped his visit with a detailed email description of the heat. Yes, the heat.

Andrew's Kansas thermometer - without all the digital whatnot. Photo: Artzer

Record high temperatures were set in Kansas last week and in other places too (Texas recorded highs above 100). The heat, however, was not the result of warm air mass streaming north from Texas or Mexico. Nor was it the result of an oppressive summertime high pressure system. Also off the hook: A convective heat burst which can rapidly heat the air near a thunderstorm. So what was to blame? Compressional, or adiabatic heating. Air rushing downhill, like from Colorado to Kansas, will compress and compression brings about heating.  Andrew’s email to his colleagues included regional weather observations indicating the heat wave across Kansas, plus a picture of his backyard thermometer which he “set up several years ago; it’s exactly 2m off the ground, is mostly shaded, and also well ventilated, so it’s set up just like [an official] reporting station, just minus the digital equipment and whatnot.”

Is it just me, or is it waaaay too early to be thinking about summer-like temperatures in the mid-to-upper 90s, let alone 100-plus? Trust me, it is! Those temperatures will be commonplace soon enough and I would prefer a few more cold fronts before jumping into the oven.

Can you imagine living in the pre-HVAC days? That would be a looong time ago, by the way, as even the Ancient Romans had a way of circulating water through the walls of houses which brought about a type of evaporation cooling. Even in the 1300s, evaporative coolers — affectionately known as swamp coolers — were a popular purchase in Iran. Air conditioning, the type based on compressing, liquefying then evaporating ammonia, didn’t come around until the early/middle 1800s when inventors discovered how to chill air and make ice. In 1902, electricity and Willis Carrier brought about the age of modern air conditioning. Life as we know it was born.

Mid-90s in Kansas, 100s in Texas. Image: Artzer


It’s possible to beat the heat, hard as it is to believe, without the benefit of electricity and ammonia. An article on Straight Dope from more than 10 years ago was resurrected by a couple of days ago stating, seemingly against common sense, that wearing black clothing can keep you cooler than wearing white clothing. The theory is simple: the color white reflects sunlight — radiant heat bombarding the surface of the Earth and all of us standing upon it. This is a good thing and this is a true good thing. However, and this is where physics, Straight Dope and io9 challenge convention, radiant heat is not only coming from the sun — it’s coming from you, specifically your body. Meaning, though the outside of your white T-shirt is reflecting sunshine away from you, the inside of your white T-shirt is reflecting your own heat back to you. Not good. The solution is to wear black, not white.

And you thought the nomadic Tuaregs of the Sahara wear black only as a fashion statement? Photo: Wikipedia

The color black absorbs light and radiant energy. Again, seemingly and most definitely against common sense, if black absorbs heat, why the heck wear it? As usual, there’s more to this than meets the eye (or skin). The trick is to combine the black clothing with a light breeze. Stay with me. Without a breeze, your black T-shirt is a heat magnet and you’ll feel hotter for sure than when wearing white. A breeze however, whisks the heat away while keeping you cooler under your black T. Black is the new white. Who’d have guessed?

But wait — there’s more!

Clothing is key to moderating your temperature outside. But there are also other strategies. It’s no accident so many people around the world live near the coast. Commerce and travel are certainly main reasons for coastal populations, but it is indeed cooler at the coast — sometimes up to 20 degrees cooler. Gentle breezes near the coast help sweep the heat inland (aided in no small way by convective heating inland), while evaporative cooling keeps the thermometer lower than regions even as close as 15 or 20 miles inland. The coast can also be home to more clouds than inland locations which can help absorb and diffuse solar radiation.

What about what you put in your body? It’s 2012 so you know by now that drinking alcoholic beverages on a hot day leads to dehydration. Certainly not a desirable condition while enduring temperatures on the upper end of the comfort (and discomfort!) scale. Instead of a cold beer after cutting the grass, hydrate with plenty of water (save the beer for later). Just this past Tuesday the Thai government issued warnings about the approach of the extreme heat season. Among many other tips, they suggested herbal drinks to reduce the body’s heat, including bael, pandan, Asiatic pennywort, sappan, chrysanthemum, and “Tre-Pala” drink formula (a combination of three herbs: Myrabolan Wood, Beleric myrobalan and Indian gooseberry). You probably won’t find that list of ingredients in many places here in the States, but all your body really needs is water — and plenty of it. Even most casual or moderate physical activity doesn’t bring about the need to consume those popular sports and energy drinks that claim to replenish your body’s electrolytes. Water is the key to staying healthy in the extreme heat of summertime that for most of us is right around the corner but for some of us is already here (right, Andrew?).

There are more ways to beat the heat, of course. Limit your time outside and your exposure to the sun. Use sunscreen. Work at night. Get a good night’s sleep to help your body prepare for and then endure the stress of being outside in the heat. Relax and limit your exertion. Jump in a pool, lake or river (never dive into unknown waters). An old Russian remedy suggests putting sour cream on a sunburn. Maybe that’s putting the cart before the horse for this article, but file it away for future reference just the same.

Sweat - your own personal HVAC system. Enable it by drinking lots of water. Photo: Wikipedia

Lastly, we’ve been talking about evaporative cooling, both mechanical in the form of evaporative/swamp coolers as well as compressing/liquefying/evaporating ammonia, but let’s not forget sweating. This is your personal, biological air-conditioning system that cools your skin as your perspiration evaporates. If it’s a hot day and you’re exerting yourself outside and you notice you’re not sweating, you’re in serious trouble and likely on the way to dehydration, heat exhaustion and even heat stroke. Take immediate steps to hydrate yourself and to seek shelter from the heat. Seeking medical attention is likely a good idea, as well.

It’s April. I’m already counting the days to October (156, as of today).




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