hello im new to snakes and after a tussle with mum and dad im aloud a snake. Today i went to get a small plastic vivarium ( approx 17" by 11"). Okay, so i got a heat mat which is the exact same size as the viv. Will this be okay to heat up the whole viv? I understand they need a cooler spot but i thought if i leave a spot with no substrate and a hide over it this will be the hotter area. The mat is 12 watts. So to confirm, ive got a 17 by 11 inch plastic viv on top of a 17 by 11 inch heat mat, wood chippings substrate, a water bowl, and a hide with no substrate underneath. Is this okay? sorry if it didnt sound clear im in a rush lol. Thanks for any help.