A light, breathable material like cotton will likely keep your face cooler than medical and N95 masks made from synthetic materials, and in the right configuration can be effective in preventing contagion, according to new research by Taher Saif, a professor of mechanical science and engineering at the University of Illinois.
Saif’s team tested 10 common fabrics, from 100 percent cotton to polyester and silk blends, to see which best balance comfort and droplet-blocking impermeability. The “sweet spot,” he says, is a two-layer mask made from a cotton T-shirt, which comes close to matching a surgical mask’s efficiency in stopping potentially infectious droplets from coughs and sneezes and is about twice as breathable.
All-cotton tested best, but up to 40 percent polyester will do the job, Saif says. “I’m not a cloth expert. I just buy things from Walmart and Target,” he adds with a laugh. “Our study showed that if you have these layers on top of your mouth and nose, you don’t have to have an official mask where it goes with the elastic behind your ears. You can just wrap it around your nose and mouth, like a bandana.”
Lighter, softer cotton coverings can also help you avoid chafing, heat rash or inflaming a skin condition like eczema or dermatitis, says Carrie Kovarik, an associate professor of dermatology at the University of Pennsylvania’s Perelman School of Medicine and a member of the American Academy of Dermatology’s COVID-19 task force.
“They make masks out of a lot of different material, so you want to feel it and make sure it’s something that feels soft against your skin,” she says. “A lot of people are making masks for fashion, they want it to look nice and pretty on the face, but make sure it feels good.”
2. Keep it dry
Cotton traps less air and moisture than standard medical and industrial masks, and it’s more absorbent, but if it gets damp due to breathing and sweating it can be less effective in filtering respiratory particles, not to mention uncomfortable and abrasive to the skin.
“Try to stay in well-ventilated locations to keep air and vapor mixing, which can help evaporate any extra water (and also keep the rest of your skin/body feeling cooler),” says Jennifer Vanos, a biometeorologist at Arizona State University who studies the effects of heat on health.
Vanos also suggests trying masks made of especially absorbent materials like bamboo, which “can absorb up to three times the amount of water as cotton.” Hemp also wicks moisture well, and washable hemp-blend masks are widely available online, although like bamboo they tend to cost more than cotton face coverings.
3. Time trips to beat the heat
Avoid going out at the hottest parts of the day and for extended periods. Stop at home between errands if you can, to cool off and doff your mask. When you do have to be out, stay well-hydrated and seek the shade.
Being cognizant of the heat is about much more than keeping your mask fresh. “We have major issues every summer with heat exhaustion and heat stroke and heat-related deaths,” the Mayo Clinic’s Poland says, and older adults are “definitely at increased risk.”
An ice pack or damp cloth applied to the head or neck can help you cool off — just take care not to get your mask wet or touch your face. Poland notes other heat hacks he’s observed traveling in parts of Asia where mask-wearing has long been routine.