Your coat pocket is the best skincare cooler.

The easiest way to keep skincare from freezing in extreme cold is to keep it against your body, not in checked luggage or an unheated car. Body heat is free, reliable, and always with you.

Freezing destroys most skincare products. The water-based formulas separate, preservatives stop working, and you end up with a grainy, useless mess. Even products that survive freezing might not be safe to use later because the structure is compromised. So prevention is worth the hassle.

If you’re traveling by plane, put your skincare in