Tonight Doc Rey was in a farm to check on brooding. When he got there late in the afternoon, he asked that additional heating source be added. Not contented with what science suggests, he set to eat dinner and decided to stay longer. The sky was dark and the wind was starting to blow stronger.
Again, do not be contented with the suggestion of 1watt per bird during brooding. Observe and use your senses. Your eyes and ears will tell you if the chicks are comfortable and contented.
Remember....they need enough heat, but equally important - they need fresh air that circulates. Let the fresh air enter and exit, not just circulating inside that becomes stale.
In cold weather, like tonight, do not put curtains or wrap the brooder's walls....instead, add source of heat.
Think of installing wind breakers :)