If you have some sort of thermometer (aquarium ones work really well and are cheap
) you could put it in the center of the light ring, 95 degrees is optimum for newborn chicks up to 1 wk old, it can be up to 100, so long as they can move freely out of the ring if they feel warm.... then 90 degrees up to 2 weeks old, 85 up to 3 weeks old, room temp is usually fine after that, they will be noisy if they want a little warmth to snuggle
Hope that helps
That picture is the height mine is at for 90 degrees with a 60w.