Newly hatched chicks need to be kept warm to maintain their body temperature, as they are unable to regulate their own body temperature. The ideal temperature for chicks, seven days old or younger, is 95 degrees Fahrenheit (35 degrees Celsius). Week two is 90 degrees Fahrenheit (32 degrees Celsius), week three is 85 degrees Fahrenheit (29 degrees Celsius), and each week declines by five degrees Fahrenheit until chicks are ready to live outside. After four weeks, chicks can handle temperature fluctuations much better than four-day-old babies.

It is important to observe the behavior of the chicks to ensure that the temperature is appropriate. If the chicks huddle up in the middle directly under the heat source, the brooder is too cold. If they move to the edge of the brooder away from the heat source, it is too hot. A heat lamp or radiant heat plate can be used to provide heat in the brooder.