Heat tracking occurs when pressure is applied to the lawn from foot traffic, lawn mowers, fertilizer spreaders or anything else that can compress the leaf tissue down to the ground below. When this pressure is applied at the exact time frame (usually early afternoon at the peak heat of the day) that the turf is at its wilting point or entering dormancy stage it breaks the leaf tissue at the base of the crown of the plant causing an immediate killing (usually within 24 hours) of the leaf tissue. Although this damage appears as herbicide or fertilizer burn from tire marks, it is simply caused by natural processes. The only indication that this may occur ahead of time is seeing footprints on turf from leaf tissue not rebounding quickly after being compressed.
This is the same type of damage that can happen on turf in late fall or early spring when the same pressure is applied to the leaf tissue when it is frozen but the crown is not. This usually results in frost delays at golf courses in the area, as the grounds department tries to prevent similar damage. (Hopefully the thought of frozen turf helps cool off whoever is reading this).
I have also attached a link to the website that covers this topic here