Heat Mat not getting tub Hot Enough

[mpgeckos]

Hi I have a 4 month old leopard gecko housed in a 12 qt tub. I have an Ultratherm heat mat 6x11 and zilla thermostat. Over the summer my house temp was 80 and the tub’s probe on the digital thermometer (Pangea brand) was reading 91f. House temps are cooling off now hitting a low of 73f. With this drop the tub’s temp right over the mat plummeted to 82-84f despite my raising the thermostat to 93-95f. I double checked with my temp gun to see that the temp was indeed low. The tub is sitting on the mat but the edges have a little raise so the middle of the tub is not directly on it. It didn’t seem to be affecting the temp before though. I have paper towel for substrate. What can I do to get the temp up?
Thank you for your help!

 

[acpart]

Check the temperature inside the warm hide and see if that's high enough. Something else that can work is to tape aluminum foil under the heat mat so that the heat mat is sandwiched between the bottom of the tub and the foil.

Aliza