Do they still need a heat lamp at night?

[ChickenHawk12]

They are 3 weeks old yesterday/today. I've been so nervous for 3 weeks about this stupid light causing a fire. They should be at 75 degrees now, according to the brooding thermometer I have. It's around 80 during the day here, in the 60's at night. My air conditioner is running, set to 70 overnight. Should I still leave the light on when I go to bed? I just turned it off and all the lights off in the house, and they were sleeping but when I turned off the brooder light they started cheeping a lot. I should turn it back on, right?

 

[Folly's place]

At three weeks of age they still need the heat lamp. A warm area and a cooler area in their brooder, so they can find a comfortable spot, is necessary. When they are fully feathered normal temps will be fine. Mary