The active ingredients in sunscreens need to be protected from harsh, hot and bright elements -- just like your skin. Avoid storing bottles of sunscreen in your car, golf bag or beach bag when not in use. Long-term exposure to heat and sun can turn sunscreen from a skin protector to a simple moisturizer in no time flat. Instead, when you're not having fun in the sun, keep it in the fridge. The cool, dark environment preserves the lotion, and the chilled SPF feels good on a warm, balmy day. And remember: Wear sunscreen even as temperatures drop. Your skin will thank you.