Those of us who live in warmer climes (or have in the past) have few worries about keeping our stray and feral cat friends warm in the winter time. We worry about keeping the cats dry in rainstorms! However, those who live in high altitudes or snow country are more concerned with keeping cats warm in the winter time.
For cats that live outside in the weather, shelter is the most important thing you can provide them. Turn the opening away from the direction of prevailing winds. Most of the time, this means turning the entrance to the east. In some areas, this may differ, so pay attention to where your storms come from. If they usually come from the north, turn the entrance to the south. The "igloo" style dog houses are especially good for this use because they have a small transition space from the outside to the inside. Kind of like a porch. Raise the shelter off the ground. Put a few bricks under it and make sure it is steady. You just want to make sure that the rain and snow have a harder time getting in. Also, you want to get the floor off the ground. You might think that the air going underneath would make it colder, but when we look at homes, we see them off the ground, with skirting around them. Use the same principle for these shelters. Line the bottom of the shelter with heavy cardboard. It provides insulation without adding bulk. Also, cats like to chew on it, which is a natural response to the smell and "giving firmness" of the cardboard. Then, put some carpet scraps on top of the cardboard. This provides more insulation and something soft for the cats to lay on. Additionally, blankets can be added and bunched up by the cats for a cuddly soft place to snuggle. Don't feel limited to blankets, as old towels work well, too.
If your cats live in a sheltered, but large space, such as a garage or other open space, your first job is to stop the air leaks. After that, see if you can enclose a smaller space for the cats. Treat it the same as for the outdoor cats.
Provide private shelters that trap heat, like the igloo houses or other shelters. In severe climates, this is preferred. Electric blankets can short out because of claws, so don't use them unless you don't plug them in and never plan to, again. Throw away the control unit! If you think you need some heat, use an overhead sun lamp. A strong spot light is great, but a heat lamp works, too; without lighting up the neighborhood. Put the switch on a timer. Only use the lamp for 2 hours at a time, then off for at least half an hour before it comes back on. This will add warmth and not break the bank or start a fire. Regular light bulbs work, too. Be sure the cats have protection from the cement flooring. All the cold from the ground will come right through it. Put down cardboard, carpet scraps or plywood.
If you are lucky enough to live in a milder climate, provide shelter to keep the elements out and something absorbent to take the wetness off the cats. They can get sick from being wet and chilled. The heat lamp idea is good, but not for small, enclosed spaces. Blankets, toweling, and cardboard are excellent. Don't use carpet in wet winter weather. It tends to trap moisture and can cause mold problems. It is better to use things that can be thrown in the washer or replaced easily. You will need to change the "bedding" frequently - no less than twice a week.
Your colony will thank you. They should weather the winter well, and come through with good health.
Frostbite and Snow Removal Chemicals
Snow and snow removal chemicals should be removed from your cats paws immediately. Never allow your cat to clean its paws if it has walked or run through these chemicals. Frostbitten skin is red or gray and may slough. Apply warm, moist towels to thaw out frostbitten areas slowly until the skin appears flushed. Contact your veterinarian as soon as possible for further care. Snow removal products should be stored out of the reach of cats and small children as their toxicity varies considerably. You will need to provide a litter medium that won't irritate the raw and healing skin of the paws. Shredded newspaper is great, but needs to be changed twice a day.
