Wind chill is the perceived decrease in air temperature that your skin feels when it's exposed to moving cold air. That cold air makes your exposed skin lose heat and moisture faster than normal. So when the wind chill is real strong, all the problems that dry cold winter air causes are increased and intensified. While you should always apply a moisturizer to protect exposed parts of your skin before going outside in the winter, do you need to rethink that moisturizer to ensure that it protects against blistering cold wind and its wind chill? Yes, and I'll explain how in this episode. Hello, I'm Dr. Neal Schultz And welcome to DermTV. In the DermTV episode on choosing a moisturizer for the winter, I discussed different weights of moisturizers and mentioned specific ingredients to look for. But to understand how to help prevent the more severe problems that wind chill cause for your skin, we need to dive a little deeper into how moisturizers work. There are two main types of ingredients in most moisturizer 06emollients and humectants. Emollients work by forming a thin film... like a barrier layer... on top of the skin that traps water in the skin and prevents its loss. Emollients are better than humectants for wind chill protection for two reasons. First, they decrease water loss by evaporation, and evaporation causes you to lose heat in addition to water. Second, emollients, by virtue of their barrier nature, literally provide a layer of insulation to further slow heat loss. Examples of emollients are dimethicone, silicone, mineral oil โ€“ which is really harmless -- lanolin, petrolatum, ceramides -- which are the major lipid constituent of the top layer of your epidermis -- and of course, naturally occurring skin lipids. Now lets move onto the second main type of ingredient in moisturizer umectants. They attract and absorb moisture, even from the air, which they can then share with your skin. But the air involved in wind chill has very little moisture, so these ingredients, like glycerin, hyaluronic acid, aloe vera, and propylene glycol, are not that helpful for protecting the skin from the extreme effects of wind chill. So as you knew, not all moisturizers are created equal, and now you have a rational basis with which to choose moisturizers to better protect you from the uncomfortable effects of severe wind chill.