No, it’s not, and you should stop wearing them in the summer.
This is short and sweet — and gives you the answer to how to feel cooler in the summer.
Please take pity on the little ones. They don’t know that polyester shirts ( or T-shirts) will make them feel the heat MORE… actually up to more than 10 degrees. If it’s 25 outside, and your little one has a T-shirt on, under that T-shirt the heat may feel like about 35 to them. And to you too. If you are wearing T-shirts as your summer shirt, or putting one on your child. please think again.
The following section is from a column I published a few years ago.
And now to one of my pet peeves. Again. I feel sorry for people who suffer in the summer heat. I don’t feel sorry for people who suffer in the summer heat but who insist on wearing polyester and knits. A T-shirt is a knit – just like a sweater, only thinner. Poly-cotton blouses, shirts, skirts and pants hold heat against your body. You may be wrinkle-free but you will feel the heat more than if you wear natural fibers in a woven fabric. Anyone who wears just natural fibers in the summer knows this.
So now, here is the proof. From the National Collaborating Centre for Environmental Health: Quoting one of several studies: “It was found that local sweating, and thus thermal stress, was higher with polyester fabrics than cotton fabrics…The onset of sweating was earlier, self-reported thermal sensation was warmer, pulse rate was higher, and changes in body temperature were greater among subjects wearing polyester versus cotton clothing. Subjects also felt wetter in polyester…. Skin temperatures were higher with polyester.”
Did you get that? Your heart rate goes up, your skin surface temperature goes up, you sweat sooner and you feel hotter than if you wore cotton.
Read the study, and check out their sources.