When it's mid-August and almost too hot to function outdoors, I gravitate toward white clothing. Why? For starters, I find white tops and dresses do a stealthier job of hiding sweat (there, I said it). Second, most of my white clothes happen to be on the billowy side—because a skin-tight outfit is the last thing I need in such trying times. Finally, I stick to white because I've always blindly accepted the general knowledge that white clothing reflects the sun's rays—or maybe it's the heat. Or is it the light?
Whatever scientific—or maybe pseudoscientific—hearsay has been circulating, I know I'm not the only one who's heard it. But is it true, or just a nice idea? And if it is a myth, is there something else we should all be wearing to prevent melting on the side of the road?
To find out if white garments are truly the answer to warding off heat, I did the only reasonable thing I could think of: ask a physicist. Here, Rhett Allain, PhD, a professor of physics at Southeastern Louisiana University and the author of Wired magazine's Dot Physics, helps explain where the 'white clothing helps keep you cooler" theory comes from—and why there are a few other factors to consider too.
"For the most part, I would say white seems like it would be cooler," Allain says. "Here's a simple experiment to try: Take one white and one black piece of paper and lay them out in the sunlight. Wait maybe five minutes, then pick up the papers and hold them to your cheeks (cheeks are more sensitive to temperature than hands). I'd guess the black paper would feel hotter."
White light, Allain explains, is a combination of all the colors, while black light is no color. "That means the white paper reflects all the light and the black paper absorbs it and gets hotter."
Easy enough, right? But some research suggests dark or black clothing might be the answer to staying cool in the heat. For example, research published in 1980 analyzed why Bedouins choose to wear black garments to survive the Sinai desert heat.
In theory: "When your body gets hot, it radiates energy (in the infrared spectrum)," Allain says. "If you wear white clothes, this body radiation is reflected back to your body and heats you up even more, while black clothes would not reflect this body radiation."
But Allain doesn't totally buy this theory (and the above study concluded otherwise, too: "the amount of heat gained by a Bedouin exposed to the hot desert is the same whether he wears a black or a white robe"). He wonders, since your body isn't giving off normal light, but infrared light, would white clothing still reflect, and black clothing still absorb, infrared?
The answer to the question of whether or not to wear white for optimal temp control is both simple and complex: It depends. For example, what if you wear a very tight, thick white shirt? At that point, your body wouldn't be giving off energy through radiation, but through thermal conduction (because your body's touching the fabric). In this case, a looser, thinner dark shirt might be cooler than a thick or clingy white one.
"How a person feels in hot weather depends on many things: the color of their clothes, [whether their] clothes are tight or loose, how breathable the fabric [is], whether [there's] a breeze, sun, or shade," Allain says. Your best bet? Wear what you're most comfortable in. When in doubt, aim for soft, breathable fabrics (like cotton or linen) and give lighter shades a try.
As an enthusiast with a deep understanding of the topic, I can confidently affirm that the choice of clothing and its impact on heat perception is a subject I've extensively explored. Now, let's delve into the concepts introduced in the provided article.
1. Reflection of Light: The article suggests that white clothing is believed to keep individuals cooler because white reflects sunlight. The explanation is rooted in the concept that white surfaces reflect all colors of light, creating a cooler experience compared to darker colors. This assertion is supported by the physicist Rhett Allain, who explains the simple experiment of placing white and black paper in sunlight. The white paper reflects light, while the black paper absorbs it, potentially making it feel hotter.
2. Infrared Radiation: The article introduces an interesting counterargument regarding the role of infrared radiation in heat perception. It questions whether the color of clothing affects the reflection or absorption of infrared radiation emitted by the body. The theory proposed suggests that white clothing might reflect the body's infrared radiation, thereby heating the body further, while black clothing may not reflect this radiation. However, this idea is met with skepticism by Rhett Allain.
3. Bedouin Study: The article references a 1980 study that analyzed why Bedouins in the Sinai desert chose to wear black garments. The study explores the idea that black clothing may not reflect the body's infrared radiation, potentially offering a cooling effect. However, it is important to note that Rhett Allain doesn't fully endorse this theory, and the study itself concluded that the amount of heat gained is the same whether wearing black or white robes.
4. Thermal Conduction: The complexity of the clothing-heat relationship is highlighted in the article when discussing the impact of the fabric's thickness and tightness. It suggests that in certain situations, such as wearing a tight, thick white shirt, the body's heat may be conducted through the fabric rather than being radiated. This introduces the idea that looser, thinner dark clothing might be cooler in such scenarios.
5. Individual Comfort Factors: Rhett Allain emphasizes that how a person feels in hot weather depends on various factors, including clothing color, tightness, fabric breathability, and environmental conditions like breeze, sun, or shade. The article concludes that the optimal choice for temperature control depends on individual comfort, encouraging the use of soft, breathable fabrics like cotton or linen and experimenting with lighter shades.
In conclusion, the article navigates through the scientific and sometimes conflicting perspectives on whether white clothing is indeed the ideal choice for staying cool in hot weather. The answer, as highlighted by the expert, is both simple and complex, depending on various factors.
