I have 5 7 wk old chicks who I moved outside about 5 nights ago with a heat lamp. I want to transition them out of using the heat lamp and am wondering if it is ok. They have small wooden crate (old fruit/veggie crate) that I filled with woodshavings and put in an old dog crate that is covered with a towel in the chicken coop. They all fit in the wooden crate to snuggle at night. The low for tonight is supposed to be 47 degrees. Is that too cold for them or will they be ok keeping each other warm?