Rats! You left the bug spray/kerosene/dish detergent in the unheated cottage over the winter. Come opening-up weekend, what can you salvage? A whole bunch of stuff, it turns out.
Bug repellents and sunscreen
DEET-based products can withstand freezing and should still be good to go in the spring; natural sprays that use citronella and essential oils, on the other hand, can degrade. Using them won’t harm you—but they won’t work very well. (Pest sprays and insect poison bait traps, by the way, can withstand freezing and remain potent. Sorry, ants.) As for sunscreen, it can handle extreme cold better than it can handle extreme heat. Still, test it: if it smells bad or has changed colour or texture, better buy a new bottle.
Liquid detergents and soaps that freeze and thaw a few times may not retain their formulations—thick gels will turn runny, for example. Shake vigorously to recombine, and save them. Ditch powder detergents; they often absorb water over the winter and become chunky and useless. And bleach? It only has a shelf life of about a year anyway; over time, its active ingredient, sodium hypochlorite, breaks down into boring old salt and water. Extreme temperatures unhelpfully speed up this process—so don’t count on it if you truly need to disinfect something.
Tool shed products
Many products with low freezing points, little water, or no additives—chainsaw oil, lubricants, acetone, mineral spirits, barbecue lighter fluid, butane, kerosene, wood preservatives, and paint thinner—can withstand winter. Keep them. But paint can be compromised by temperature fluctuations. Plus, condensation can form in half-full cans, adding water to the paint. No good. Even if the paint looks normal, it won’t perform as well as the stuff from a new can.
The cold won’t hurt shaving cream, moisturizers, hair spray, and air fresheners. But it might mess with condoms, birth control, and other medications. Just don’t even.