It is important to watch the chicks too. If they seem to be failing, weak or very hot you need to weigh your choices. Open the incubator and take them out, or let them stay. If you open it up, you take the chance of any eggs that haven't hatched out, shrink wrapping the membrane. Leave them in and they may have issues.
I left mine in once for a 48 hours and when I took them out and dipped their beaks in water, quite a few would go into convulsions.
I had to go very slowly and dip each one with the problem about every 10-15 minutes to help them rehydrate. I would hold them while the shook and gently put them down. After about 5 hours they were drinking on their own.
Now I try to get mine out by no later than 36 hours.