Just because it’s cold doesn’t mean you can’t sunburn. Snow, in fact, is an excellent reflector/doublebroiler. Ergo, slather on the sunblock, which reflects the sun (as opposed to sunscreen, which absorbs UV radiation though might not ward off harmful UVA rays, and can contain ingredients — e.g., benzophenone and homosalate — with spotty health records). The good news: CLIMB ON! SPF 30 MINERAL SUNBLOCK ($18, climbonproducts.com) has only one active ingredient — zinc oxide. Nontoxic and biodegradable, the lotion also nourishes your skin with ingredients like grapeseed oil, fair-trade shea butter, and aloe vera. It goes on with reassuring thickness and offers solid, water-resistant protection for any-season solar intensity.