Good. So I'm done fretting over the heat issue. I used a 250W heat lamp at first, which was way too hot for them. They hated 95 F and were panting in the corners, so I switched to a 60W incandescent, which maintains 70 F in the brooder (with blankets on top) when it's 59 F outside. My chicks are about 2.5 weeks old and not huddled up; just milling around chirping contentedly and playing on the ladder perch I made. They're growing very quickly and have hearty appetites. So 70 it is, even though they're not supposed to like it!