I don't think being outside causes illness. I think germs cause illness (and then only sometimes). If my kids want to go outside with no coat and no hat and no shoes when it's 32 degrees and sleeting it's ok with me. When they are cold they will come back inside. Don't feel you need to call me about it! If you see them practicing their hatchet throwing or sacrificing small animals THAT would be the time to call me.