Our's typically never saw sunlight, or not very much of it atleast. We'd wait until dark to turn them out. When we'd do so we'd shut the cooler down and leave them in for about 10 minutes to let the temp rise gradually that way they didnt go from ~50* to ~75* instantly. Did it help? Probably not. But we felt it helped to cut down on getting one sick by not having that initial "temperature shock" so to say.