I will get the name brand of the heater when I get home, as I am at work now.
IT was a large room heater with an internal thermostat. You can set the lower temp to turn on the heater when it gets down to that temp, the the upper limiter to turn it off when it hits that temp.
The room was a 9x12 rounded ceiling room with a very LOW ceiling 6.5 feet at the highest point, with hard wood floors, packed with books and book shelves. The snakes were mostly in tubs, with two king snakes in large tanks w/ screen tops. All the snakes and asf's were on wire rack shelves.
The ones I lost were on the top shelves, closest to the ceiling.
The room was at AT LEAST 98 degrees for I would think 6 hours, no fan except the force from the heater, which was large nearly 2 1/2 feet tall.
The temp limiter must have burnt out, it is the only thing I can think of.
My tarantulas were on lower shelves and survived, and the one bp that was on a lower (waist high) shelf survived.
my rats, larger colubrids, t's and one bp survived due to being on the lower shelves where the heat didn't rise.
I started fans immediately and within half an hour to 45 mins, the temp had gone down to 82, I have kept the fans on, and will go home and check them during lunch.
My two larger kings were in their water bowls....And my black mexican king is in the middle of shedding, i soaked her in room temp water in the bathroom for a bit too, and the surviving bp.
I lost Tarantulas once to an over heating which is why I switched to a (I thought) better, more reliable room heater to keep the room at 78-80 degrees...
I think the room size and shortness of ceiling had to do with the heat build up near the top which cooked the snakes....
I want to cry, but am just numb right now... I have had lucille for a few years now and losing her was hard...