The temps on the body are all different; CORE body temp is around 98.6. I'm usually 99.2-99.5. However, just the tongue is only about 85F, so imagine our hands are around that or even cooler.
Anyway, I suggest a warm bath (range about 80-88F). The bath tub is good for bigger ones. I get the water to a certain temp as it comes out of the facet, then let it fill up. I also check with my hand that the water temp is consistent. Also, if you have it on the warmer side, it doesn't hurt to let it sit for about 5 minutes. Just remember to give the snake a spot where it doesn't have to keep swimming.