Hey! I pulled some chicks out of the incy and put then into a lit tote-box brooder with shavings (pine) from Tractor Supply and they all started going into seizures within about 5 minutes. We yanked em out and put them on a towel atop a warm heating pad. Within an hour they were normal again. The only thing we figured was that the fumes from the shavings being heated by the lamp caused a neurological reaction. Very scary! I only use Bermuda hay or corn cob pellets (when they get older) now. Or if it's warm outside, I will use the shavings, but not with a heat source.
That's scary. I don't know anything about hatching, but I read a write up once that this guy covers the bottom of the box with chick starter for the first couple of days. That way he knows they have access to the food, it gives a good footing and is fairly absorbant. Don't know if it's a great idea or not, but at least it shouldn't be toxic to them.
Is it a new plastic tote? If so, could the heat be burning off the release agent in the tote?