How hot should the chick brooder be?

As a general rule, you want your heat lamp at a hight
that provides 95 degrees on the floor below for the first week.
Every week you can raise the lamp enough to drop the temperature by 5 degrees
until the chicks are fully feathered and can manage without the heat lamp.

A good way to make sure the temperature is correct is by watching the chicks. If they are crammed in close together under the light, they are trying to get as much heat as possible and need the lamp closer. If they are seperated and on the outsides of the brooder, it is too hot and they are trying to get away from the heat so raise the lamp.

Before they have their feathers, chicks are very susceptible to cold weather and drafts.
Try to keep any breeze blocked and the temperature as constant as possible.