As I hurried to an appointment one recent afternoon in New York City, the harsh sun seemed to set my skin and hair on fire. Sweat pooled under my sunglasses, and my T-shirt and shorts stuck to my damp skin. I was miserable.
I should have been used to the heat. I grew up in southern India, where the temperature routinely swept past 100 degrees Fahrenheit. But I had abandoned all the tricks and strategies I had used then.
To begin with, I was walking outside at about 3 p.m. In India, I rarely ventured out between 11 a.m. and 4 p.m., or if I did I was fully equipped to face the sun. I usually carried an umbrella, much as women in Victorian England carried parasols, to shield my head and face. And I wore salwar kameez, a tunic and loosefitting bottoms made of thin, gauzy cotton.
It turns out that these methods, employed all over South Asia, are rooted in solid science, even though I didn’t realize it then. As climate change sends temperatures soaring around the world, people who are not used to coping with heat could stand to adopt a few strategies from regions that have faced hot weather for generations.
In New York I only ever carry an umbrella when it’s rainy, and rarely wear a hat except at the beach. “But in a situation where you’re out in the direct sun, having something to protect you from that direct sun radiation is important,” said Dr. Jill Tirabassi, a sports medicine expert at the University at Buffalo.
Likewise, wearing little clothing in an attempt to stay cool (or cultivate a tan) exposes you to dangerous solar radiation. A better option is to cover up. “You actually want to have breathable layers that will help transfer your heat out,” Dr. Tirabassi said.
People in hot regions, including African deserts, similarly dress in thin, loosefitting clothes, in light colors that reflect the sun’s rays, let in air and facilitate the evaporation of sweat, rather than trap the heat as darker colors do. Clothes made of thin cotton, linen or bamboo are the most breathable, and synthetic fabrics, like polyester and nylon, the least.
“Having that sweat evaporate is a really important way to cool your body when you’re moving or exercising,” Dr. Tirabassi said.
One habit I picked up after observing the locals during summers in France is to spritz my face with water. It can also cool the skin — as long as it’s not too humid — when the water evaporates.
“It’s kind of replicating what the body does when it sweats,” said Dr. Cecilia Sorensen, an emergency medicine physician and director of the Global Consortium on Climate and Health Education at Columbia University.
“Having that layer of cool water or precipitation on your skin actually speeds up your body’s ability to release heat,” she said.
Cool, damp cloths can accomplish the same goal. In northern India, men often wrap a wet scarf or towel around their neck or their head, said Sanjiv Phansalkar, a rural development expert at the nonprofit VikasAnvesh Foundation.
In Nagpur, Dr. Phansalkar’s hometown, “anybody going out in the street in the summer without their head and ears being covered by a cloth will be immediately stopped by a stranger and made to do so,” he said.
Dr. Sorensen said this practice makes scientific sense: The neck is replete with blood vessels, which widen at high temperatures. The dilated vessels carry more hot blood from the core of the body to the skin, where heat dissipates into the air. In fact, when people turn up in emergency rooms with a heat illness, doctors often pack the neck area with ice and cold towels to rapidly lower their body temperature, she said.
Hydrating with fruit and vegetables
Sweating is the body’s natural cooling mechanism, but the moisture lost must be promptly replaced. That can be accomplished by drinking water, eating watery vegetables and fruit like cucumbers, watermelon and mangoes, or liquids like soups — yes, soups. People in the tropics often eat hot soups, in order to cool off by sweating.
“Everybody knows hydration, hydration, hydration, but what we miss is that hydration doesn’t necessarily mean only drinking water,” said Dr. Asim Shah, a professor of community and family medicine at Baylor College of Medicine in Houston who has studied the impact of heat. He said water should be combined with electrolytes, electrically charged minerals like sodium, calcium and potassium that are needed for nerve and muscle function and maintaining pH levels.
When I was growing up in India, bottled water was not as ubiquitous as it is today. Coconuts, heaped high in roadside stalls, offered an inexpensive, safe and delicious alternative. Vendors would use a small machete to slice open the top of the coconut. When I’d had my fill of the cool, sweet water, I would break the coconut open and eat its moist white meat.
Coconut water is more beneficial than plain water because it has electrolytes. (Most brands of bottled coconut water preserve them, but some also come with unwanted added sugar or artificial flavors.)
Doctors generally warn against drinking alcohol in the heat because it is a diuretic and can lead to dehydration. If you do drink, margaritas make a good option because the salt on the rim can replenish sodium lost to sweat, said Dr. Sorensen, whose family is from Ecuador.
The best way to protect yourself from the sun is to avoid it as much as possible. In various cultures, that means scheduling work for the hours when the daylight is less intense.
Many people in southern India, and especially those who toil outside, begin their workday around 4 a.m. and work until no later than noon. The afternoon often includes a nap. Work then resumes at 4 or 5 p.m. for a few more hours.
“There was like a completely different rhythm of life,” recalled Krishna AchutaRao, a climate scientist at the Indian Institute of Technology in Delhi who grew up in the South Indian state of Tamil Nadu. The routine is now less common than it was in his childhood, he said, as Western rhythms and office life have taken over Indian cities.
Some Central and South American countries and some in Europe, Asia and Africa follow a similar schedule, with a nap built into the hottest afternoon hours. As unrelenting heat grips Europe, countries like Germany, which once sneered at the idea, are now considering taking midday breaks too.
Naturally cool homes
Few Indian households have air conditioning; traditional homes manage to stay cool using other techniques.
One key approach is to open windows early in the day and close them before it begins to warm up. Heavy, dark curtains block light and heat from entering the house, and ceiling fans circulate the cool air trapped inside. My family home had curtains made of khus, a native Indian grass, which we sprayed with water every couple of hours. The curtains transformed hot gusts into cool, fragrant breezes.
Many traditional Indian homes have verandas, high ceilings and walls of mud that keep the interior cool. New Orleans, where Dr. AchutaRao lived for nine years, is famous for its shotgun houses — linear buildings in which a bullet shot through the front door can in theory exit through the back door without hitting anything on the way — that allow the air to flow freely. Because heat rises, high ceilings and ceiling fans also keep the living spaces cool.
Not having such simple strategies in place can make even milder temperatures unbearable. Dr. AchutaRao recalled being in Oxford, England, when it was around 90 degrees Fahrenheit, lower than the triple-digit temperatures he was used to. But there was no ceiling fan, and the windows could let light in but wouldn’t open wide enough to allow a breeze.
That temperature “is a routine day in India, but it felt so much worse,” Dr. AchutaRao recalled.
He lamented that some of these older strategies may have become useless — for example, early mornings are frequently so warm now that even waking up at 4 a.m. may not always offer a comfortable start to the day.
Climate change’s rapid pace demands solutions that can keep houses and bodies cool even when the mercury keeps rising, he added.
“You’re no longer adjusting to one hot day or a couple of hot days, you’re looking at weeks upon weeks of having to deal with this,” Dr. AchutaRao said. “This is the cultural shift that people have to make in their heads.”