You are a worrier. I doubt I can do anything to get you to relax a little but I'll try. This behavior is exactly what you want. You are doing great.
I responded to the warmth question in your other thread. To avoid retyping some I'll just link to that thread.
https://www.backyardchickens.com/threads/how-warm-do-they-need-to-be.1498761/
Have you noticed that if you have a large group of people in a room some are usually a bit warm, some are usually a bit cool, and many are comfortable relative to temperatures. Chicks are the same way. Some prefer it a little warmer, some prefer it a little cooler. There is no "perfect" or "best" temperature for all chicks. There are a range of temperatures where they do well. When you go outside to take care of your chickens or do yard work or garden, there may be a certain temperature you "prefer" but that doesn't mean you are going to get hurt if you are a little warmer or cooler. Your chicks wont be hurt if you don't have some mystical mythical perfect temperature that doesn't really exist as long as you avoid extremes.
That start at 90, 95, 90 to 95, or 95 to 100 and drop it by 5 degrees a week is not a law of nature. People can't even agree where to start. I consider this a general guideline. To me the best brooder has one spot warm enough in the coolest temperatures and a cool enough spot in the warmest conditions. If you follow this guideline for the warmest spot they will never freeze to death or catch a chill. It doesn't matter if the far end of the brooder has ice in it as long as they have a warm enough spot. It doesn't matter if a spot is pretty warm as long as they have a cool enough spot. What I find is that my brooder raised chicks tend to play a lot in the cooler areas and go back to a warmer area if they need to warm up.
In Texas and other parts of the world, broody hens raise chicks in the heat of summer. Sometimes the daily high is in the 90's F, sometimes over 100 F. Too much heat can be dangerous. My broody hens will have them out foraging during the day, but they take them to shady areas where they can settle in the dirt which should be cooler than air temperatures. Broody hens can raise chicks when there is snow on the ground. The chicks stay out until they get cold, then go under the broody to get warm. I' trying to say that their entire environment does not have to be perfect. All they need is a spot that is cool enough or warm enough and there is a tremendous range that can be warm enough or cool enough.
Most chicks feather out by the time they are 4 to 5 weeks old. Unless you have ridiculous low temperatures they can handle colder temperatures fine by this age. Many broody hens take their chicks to the roosts by 4 to 5 weeks of age. They can't all sleep under the broody on the roosts at that age. They don't have to, they can handle the temperatures. I've seen a broody hen take her 2 week old chicks to the roosts. This was in the heat of summer where the nighttime lows were in the upper 70's. Not all could sleep under her, they were fine.
I don't believe in that 5 degrees off a week chart but some people feel a lot better if they have something like that. So I'll put this together.
1 - 7 days old = 0 weeks old = 90 F
8 - 14 days old = 1 week old = 85 F
15 - 21 days old = 2 weeks old = 80 F
22 - 28 days old = 3 weeks old = 75 F
29 - 35 days old = 4 weeks old = 70 F
36 - 42 days old = 5 weeks old = 65 F
Most chicks can handle colder than this. As I said, a guideline for the minimum temperature of that warmest spot that will keep you out of trouble. Your coolest spot does not have to be this cool. As long as it is not warm enough to cook them they will be OK even if it is much warmer than this. Just like your adult chickens can handle temperatures warmer than the minimums.
Personally I watch the chicks to see how they are doing. As long as one spot is warm enough and one spot is cool enough I have zero stress about this. I let the chicks do the work.
Dear Wife considers me old, incorrect, and widespread, but not so popular anymore.....
