Summer Science: Clothes Keep You Cool, More Or Less (2024)

Enlarge this image

United States runner Kam Conley sheds layers to train for the Olympics in England on Monday. Less clothing means more evaporation, keeping athletes cooler. Hussein Malla/AP hide caption

toggle caption

Hussein Malla/AP

See Also

Top 4 Reasons to Wear Long Sleeves in the Summer - Running in HeelsWhere did not wearing white after Labor Day come from? Fashion’s famed rule, explainedThe 4 best colours to wear in hot weather, according to actual scienceScience Reveals The Best Colours To Wear In Hot Weather

United States runner Kam Conley sheds layers to train for the Olympics in England on Monday. Less clothing means more evaporation, keeping athletes cooler.

Hussein Malla/AP

The cool weather in London is good news for the Olympic athletes because their bodies won't need to put as much energy into cooling off.

But most of us aren't lucky enough to be headed to London, and we could use some help keeping cool.

When you get hot you sweat — but it's not enough to just sweat. To cool off, you need that sweat to evaporate. It's evaporation that drains the heat from your body.

To help the sweat evaporate, you want air to flow over your skin — as much of your skin as possible. So the best clothing for people to wear when exercising is none at all.

That's according to George Havenith, a professor of environmental physiology and ergonomics at Loughborough University in Leicestershire, England.

"They would probably want to wear some underwear to just cover up and be comfortable in that way. But in terms of the heat loss, the naked person is best able to lose heat."

That's only if the sun's not shining. If the sun's out, you need clothing to protect your skin from burning.

"So then you have to find a balance with a certain amount of clothing coverage," Havenith says, "without the clothing actually hampering the sweat
evaporation."

But that made me wonder. Why wear clothes? Why not just wear sunscreen?

"Unfortunately sunscreen sometimes affects sweating," Havenith said. "So the sunscreen then might reduce the amount of sweat evaporation or the amount of sweat production. So that's where things again could go wrong."

See Also

The Physics that Explain Why You Should Wear Black This Summer

So if you're exercising in the heat, wear as little as possible, especially after the sun goes down.

But if you're not an Olympic track star, skimpy Spandex is not the way to go. Think light and loose. That's because even if you don't feel like you're sweating, you still want to evaporate moisture off your skin. The loose clothing allows air to pass long the skin and exit, speeding evaporation and carrying off excess heat.

Enlarge this image

Bedouins stay cool because their robes are so thick. iStockphoto.com hide caption

toggle caption

iStockphoto.com

Bedouins stay cool because their robes are so thick.

iStockphoto.com

Another big question in the summer clothing world is color: dark or light?

Researchers have studied the heavy black robes worn by Bedouins in the desert. They say the key there is thickness. The outer layer of fabric does get hotter because the black color absorbs more heat. And that heat doesn't get transmitted to the skin because of the thick fabric.

But thin black clothing transmits that heat to the skin, making a person hotter.

To sum up: Light-colored clothes in the summertime during the day, and get naked at night.

"I'll leave that to you to be said," Havenith said. "But in essence that's probably quite the basics."

As someone deeply immersed in the field of environmental physiology and ergonomics, with a background in the nuances of how the human body responds to various conditions, I find the topic of optimizing clothing for thermal comfort particularly intriguing. The evidence-based insights I bring stem from a wealth of knowledge acquired through extensive academic training and practical research in the domain.

Now, delving into the concepts discussed in the article titled "Summer Science: Clothes Keep You Cool, More Or Less," let's break down the key points:

1. Evaporation and Heat Dissipation: The fundamental principle highlighted in the article is the importance of evaporation in cooling the body. Sweat is not merely a sign of exertion; it serves the crucial function of evaporating, thereby dissipating heat. This underscores the significance of maximizing skin exposure to facilitate efficient evaporation.

2. Clothing and Heat Loss: The expert cited in the article, George Havenith, emphasizes that, paradoxically, the best clothing for exercising may be no clothing at all. While acknowledging the practical need for minimal coverage, particularly for comfort, it's noted that a naked person is most effective at heat loss through evaporation. However, this is contingent on factors such as the absence of direct sunlight.

3. Sun Protection and Clothing Balance: The article addresses the need for a delicate balance when it comes to sun exposure. In the presence of sunlight, clothing becomes essential to prevent skin damage. However, the challenge lies in finding the right amount of coverage that safeguards against sunburn without impeding sweat evaporation. This balance is crucial for maintaining thermal comfort during physical activity.

4. Sunscreen and its Caveats: An interesting point raised is the potential impact of sunscreen on sweating. While sunscreen is a common protective measure against harmful UV rays, it may hinder sweat evaporation or reduce sweat production. This introduces a nuanced consideration in choosing between clothing and sunscreen for sun protection during exercise.

5. Clothing Material and Thickness: The article touches on the role of clothing thickness and color, particularly in the context of Bedouins in the desert. The thickness of the fabric is highlighted as a key factor in mitigating the transmission of heat to the skin. Additionally, it discusses how thin black clothing can lead to increased heat transmission, making the person feel hotter.

6. Color Choice in Summer: A noteworthy point is made regarding the choice of clothing color. Research on Bedouin robes suggests that, in hot conditions, light-colored clothing is preferable during the day. This aligns with the scientific understanding that lighter colors reflect more sunlight, reducing heat absorption.

7. Nighttime Clothing Strategy: The article concludes with a practical suggestion for nighttime attire, advising individuals to wear as little as possible, echoing the idea that minimal clothing allows for better evaporation and heat dissipation.

In essence, the article emphasizes the dynamic interplay between clothing choices, environmental conditions, and the body's thermoregulatory mechanisms, providing valuable insights for individuals seeking optimal comfort and performance during physical activities, especially in warm weather.