That sounds like a good plan. On nice days when it's sunny take them outside once they are a couple of weeks old, they can be in 50-60's with sun and no cold wind. Just short field trips to get them acclimated to temps.
I honestly don't know why they do this. I'd say most likely Malposition. @shawluvsbirds would probably be able to say more about this.
I had some OEGB chicks hatch in Oct one year. Under a mama hen, I did set u a heat lamp over their stall I kept them in. Even mama enjoyed it. That's the only...