The primary goal of winter shelters is to keep our community cats warm and dry during the coldest months and unless you're starting with an insulated base like a cooler, that starts with a good layer inside your container designed to hold-in heat. We went big this year and sprung for large canisters of spray-on foam insulation, but if you're looking at a smaller project, you're just as well off using smaller hand-held cans. Sheets of styrofoam cut to size with an assist from mylar double-sided insulating bubble wrap also work well and while we do find that set up to be less durable, it's easier to manage those materials if you only have an indoor work space. Either of these liners combined with some layers of that insulating bubble wrap on the underside of the container lid and a nice bed of straw make sure your community cat friends will stay toasty all winter with the power of their own body heat!
