You may be buying a cup of coffee, rifling around in your bag, or texting on your phone, but you've decided for whatever reason to take off your gloves. If you keep them off, you run the risk of damage. Sudden temperature changes, whether hot or cold, can trigger eczema flare-ups in those who are predisposed to the (often genetic, according to new research in Nature Genetics) condition or who already suffer from it. "A lot of people will develop hand eczema in the wintertime," Dr. Katta says. But all of us can benefit from less exposure to dry winter air, which causes water to evaporate more quickly from the outer layer of skinand has been linked to depletion of protective fats, leaving hands more vulnerable to dryness and cracking. So, it's worth being vigilant about wearing gloves or mittens.