we have just bought this viv Popup Window 510409

and have got a heat mat size of mat is 16"x12" and a thermostat.

1 - do i put the heat mat on the back of the viv on the outside or inside of the viv???

2 - do i put the heat mat on the bottom of the viv inside under the soil???

3 - does the thermostat have be on the heat mat or in the soil????

Please help as my hubby and i are having a dispute