I think 38.5 would be a little over 1/2 degree and no a little warm is much better than too cool. As you see too cool causes late and scattered hatches as well as unhealthy chicks , crooked legs and pipping and dying. Inexperienced people are so paranoid about running a little too warm will burn the eggs up and that's just not true. I am speaking from experience not something i read or heard. A chicken egg will actually hatch in 18 days at 102 degree's. I have heard all the comments about burning eggs up and you have to get up to about 104 to start doing harm. I am not recommending anyone do this i am just stating facts. I know there are side affects about hatching in 18 days but my point is a little warm won't hurt anything. The worst that can happen is they hatch a little early but they will hatch very well. If you don't beleive me set your incubator on 104 and put an egg in it for 2 days and break it and see if there is any damage. It takes about a day for an egg to get warm to the core. Another thing people are paranoid about is opening the bator during hatching. I usually open my bator 3 to 4 times a day during hatching to check for problems like getting a leg out the pipped hole and hatched eggshell caping over a pipped egg and suffcating the chick. When i get done i simply mist the eggs with warm water to replace any moisture i lost and don't have any problem. I hope this helps as i am only trying to help.