The thermoSTAT probe is what goes between the glass and the heat pad (on the outside). The thermometer probe goes directly above the heat pad inside of the tank, measuring the hottest temp your snake has access to.
OP - You said you're seeing high temps. How high are you talking? Anything 95 or over is unsafe for your BP and you need to get a thermostat to be able to control the temperature of that heat pad.