What should I do here... ive had my BPS for the whole summer and with the A/C on, i didnt need to worry about the temps getting too hot...

I use ASPEN bedding and it seems i get a innacurately hot reading when the sensor / probe is burried in it... so where should sensors be?

I have a BP in a 20 gallon w/ aspen, where should I put the thermostat sensor? I had it on the floor covered w/ bedding... i need to know where to put it. thanks!

spare no cost, which is best thermostat?