Is the weather dry or wet? This is the most important question when choosing clothes. While the world continues to struggle with extreme heat waves, which have increased in frequency recently due to climate change, the clothes we wear are an essential element to keep our bodies cool.
The researchers found that by wearing the right clothes, you will be able to raise the temperature of the air conditioner by 2 degrees Celsius, which in the long run should help save a great deal of energy, which saves money and reduces greenhouse gas emissions.
So what are the best clothes to keep you cool in a heat wave?
Color and design
When it comes to colour, most people wear white in the summer, because white reflects the sun's rays, rather than absorbing light like black.
However, this theory becomes more complicated when we start talking about the thickness and fit of the clothes, because the heat does not come only from the sun, it also comes from our bodies, so when our body heat hits the white clothes, it reflects back on us.
In 1980, a study of why the Bedouin, the indigenous and semi-nomadic people living in the desert regions of the Arabian Peninsula, the Middle East, and North Africa, wore black robes in the desert found that the heat they were exposed to was the same whether the tribe members wore Black or white colour.
Not everyone can wear the most appropriate clothing for hot conditions at all times, but placing a wet scarf around the head or neck can help.
How is that possible?
Black fabrics absorb heat from the body, so this can play a role in cooling the body.
The secret of the Bedouins is to wear loose black clothes, especially if it is windy, as loose black clothes heat the space between the fabric and the skin, which enhances the upward draft of air, and provides cooling.
The study indicates that the amount of heat acquired by the Bedouins when exposed to the hot desert is the same whether they wear a black or white robe, and that the extra heat that the black robe absorbed was lost before it reached the skin.
So the type of clothing is actually more important than the color. However, if you're going to be wearing skimpy clothes, stick to white. Pique, a fabric often used in sports jerseys, helps create space between the body and the skin.
The type of fabric is key in keeping the body cool
"Your choice of fabric is critical," says designer and fashion blogger Heather Neuberger. "If you're wearing plus-size jeans, you'll feel hotter than your boyfriend in chiffon leggings."
And she adds, when it comes to the quality of the fabric, lightweight woven fabrics such as: cotton and silk are usually better if they are loose-fitting, and this is especially important when the weather is humid, but if the weather is dry, the fabric alone may be sufficient, because the fabric will absorb sweat. from your body and evaporates from the heat.
And she confirms that when the weather is humid and hot, the air around us is saturated with water vapor, which means that the sweat that the body has absorbed will remain on the clothes, because it has nowhere to go.
With regard to clothing, designer Heather adds that it is better for a person to wear a fabric that allows water vapor to pass through so that sweat can evaporate. "Some of the new sports fabrics do that, but cotton doesn't do it as well as it should," says Rhett Allen, associate professor of physics at Southeastern Louisiana University.
All fabrics trap infrared radiation from the body to some degree, which helps keep us warm in cool weather, but it's not ideal during hot summer days, so wearing breathable clothing is important.
Cotton, linen, nylon, and uncoated polyester are all classified as fairly breathable fabrics, which means they allow perspiration and heat to evaporate.
Cotton and polyester absorb and reflect 99% of the infrared radiation that strikes them, which is why they appear white most of the time in infrared images, but they also allow 30% to 40% of visible light to pass through, which can cause higher body temperature faster, according to researchers at the Massachusetts Institute of Technology (MIT). According to the researchers, this happens because visible light can generate heat that cannot escape like infrared radiation that an object generates.
But the body's other cooling mechanism, perspiration, also plays a role. Cotton absorbs moisture but doesn't dry quickly, so if you sweat a lot, your clothes will stay wet.
Linen is widely worn because it is highly breathable due to the fibers it contains, but like cotton it dries slowly. Merino wool has been a popular choice for outdoor enthusiasts as it breathes and wicks away moisture without retaining an odor.
Nylon and polyester are used in most sportswear because they absorb moisture and dry quickly, but they retain odor. Research has also shown that nylon has a higher ability to absorb moisture, but is slower to dry, and synthetic fibers such as nylon and polyester can cause discomfort when wet, so one study brought up the idea of wearing clothes made from bamboo, as it is a low conductor of heat.
If you really want to keep your cool, you have to undress completely for as long as it's appropriate, says George Haveneth, professor of environmental physiology and ergonomics at Loughborough University in Leicestershire, UK.