Ceramic heat emitters are ideal.
Are you sure you are heating the mouse to a high enough temperature? If the snake is constantly aiming at your hand (instead of the mouse in your hand) it may be that he smells the food but the higher heat signature is coming from your hand and not the mouse. The mouse needs to be really warm to the touch, I believe the average body temp of a mouse is around ~110 degrees or more (off the top of my head so not super accurate, but a good deal higher than human body temp) so it needs to feel almost hot.
His warm side tempuratures need to be boosted to ~90 degrees or he may not want to eat, 80 is too cold for a warm side temp and if bps can digest at this temperature (I'm not entirely sure they can) then it will be a slow process and feeding times may need to be extended.
If the animal is left alone for a period of time, husbandry is on point and the mouse is heated properly, he should eat.