If they are new babies, they need their brooder to be 95 degrees for the first week at least. Get a thermometer to put under the lamp so you know. If you are keeping them in a cardboard box, get some hardware cloth to put over it and you can cover it with a few sheets of newspaper to help keep the heat in if needed. Be careful if you do that, because they can overheat very fast if you cover it too much. Keep checking back if you cover it, keep an eye on the thermometer. You will figure out what works for your house/brooder situation. They "need" it to be warm. I think your main problem was hypothermia, which will kill them pretty quickly. Get them warmed up, put a heating pad under the brooder box if you don't have a light for tonight. Good luck, and keep us posted.