Provide your corn with a basking spot of 88-90° F and an ambient (background) temperature of 70 - 75° F. The ambient temperature should not fall below 70° F. It is vitally important to KNOW the temperatures at which you are keeping your snake(s). DO NOT GUESS!! A great way to monitor temps is to use a digital indoor/outdoor thermometer with a probe. Stick the thermometer to the inside of the cage on the cool end and place the probe on the warm end, and you'll have both sides covered at once.
Sorry, the guide is wrong then, hence me thinking it was 90. I barely needed to change anything since I am not running a thermostat and am running a rheostat (I work up, not down, to reduce risk of burns) and it was having the heat mat at around 80 when I saw this.

Thanks, guys.