You want it to be around 100-105 degrees with special attention paid to its head. It should feel warm to the touch, but not hot. Hatchlings cannot go as long as adults without food, so if he refuses the f/t I would try a live fuzzy rat. Leave it overnight if he doesn't take it immediately, it won't hurt him. Then from there I would get some size to him before forcing the switch to f/t on him.
Assist feeding is a last resort, when it means life or death and all other avenues have been exhausted. If it were to come to that, I strongly advise you to have someone experienced do it or help you. Its very stressful to them and you could easily injure the snake if you don't know what you're doing.
What are your temps and humidity? What size tank/tub? Hides? Is he in a heavily traveled area of the house?
His humidity is at 64, cold side temp 80 and 86 on hot side by my thermometer. No hides and he is in a 6qt tub. He is not in a heavy traveled area as he is in a rack in a climate controlled closet with our other bp's.