Here’s another good old-time rule that most people have forgotten:
“The floor of the brooder must be warm and dry to the touch before you add chicks.”
If the baby chicks get chilled as soon as you take them out of the shipping box, bad things happen. They lose the desire to eat and drink, and sometimes the ability to move, if they’re chilled. Cold or damp litter is enough to chill them.
Usually you should turn on the brooder the day before the chicks arrive. This is no time to try to reduce energy consumption.