I go the other way and use coolrooms to conserve heat but the problem is, its hard to keep a low ambient temperature. Insulated coolrooms work great for say less than 2 yearolds where I dont think a temp gradient is necessary, but with breeding animals a tin shed is probably better as it lets the heat go. From an environmental point of view "letting heat go" is wasting energy which must contribute to the release of Carbon to the atmosphere and accelerate the demise of our planet.