UTH's reach temps of 120 degrees + just plugged into the wall. A thermostat, found here (https://www.amazon.com/MTPRTC-Controller-Thermostat-Germination-Reptiles/dp/B000NZZG3S/ref=sr_1_1?ie=UTF8&qid=1528258805&sr=8-1&keywords=jumpstart+thermostat) regulates the temperature to what you decide so it does not burn your reptile. You plug the mat into the thermostat and place the probe in the tank so it can read the temp on the floor above the heat mat and turn it on/off as need be.
I use the same heat mat as you, but I have it connected to a thermostat. This one: https://smile.amazon.com/gp/product/B000NZZG3S/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I keep it the temp set at high 70's or low 80's depending on what cuttings or seeds I'm using it for. Our house temp ranges from 66° to 72° in the winter. At an ambient temperature of 80°, I don't think you really need a heat mat.
just found this one specifically for heat mats https://www.amazon.com/Hydrofarm-Germination-MTPRTC-Controller-Thermostat/dp/B000NZZG3S?ref_=fsclp_pl_dp_1
I have this one: https://www.spyderrobotics.com/index.php?main_page=product_info&cPath=1&products_id=23
It's a little on the pricey side but it works so much better than my previous one and it has better safety features.
If you are on a budget my previous one was this one: https://www.amazon.com/Hydrofarm-Germination-MTPRTC-Controller-Thermostat/dp/B000NZZG3S
but be warned that after 3 years it started to malfunction.
A thermostat is one of the most crucial pieces of equipment that you will need to set up any reptile tank. It controls how hot your heating element will get. Without one, heating elements alone can literally cook your snake.
Having a temp gun is good and will help you set up your thermostat.
Setting one up will vary a little bit depending on your heating element and type of tank but in general it goes like this:
1) plug thermostat into power source
2) plug heating element into the thermostat and set up heating element where you want it
3) place temperature probe in tank. Actual placement may vary by heating element but in general you want to put it in a place that will measure the hot spot in your tank and where your snake can't move it
4) monitor the surface temp with your temp gun and adjust your thermostat to make sure that your hot spot is getting to the right temperature