Before I moved it to the closet I was in the habit of upping the temp about a half a degree (F) at night and lowering it back down in the morning to compensate. That was during the summer though, but maybe there is the same amount of fluctuation during the winter. That was on my Farm Innovators which uses F. So, on a C thermostat that would be like putting it up to 37.8 at night to compensate and then back to 37.5 during the day. Keep an eye on it first to see if that might be necessary. I think even under a broody the temp will drop at night a bit if its cold out.