The heat lamps increase the "feels like" temp by about 20 degrees, in my opinion.
A 30 degree day, feels like a 50 degree day (under the lamps).
A 15 degree day, feels like a 35 degree day.
Etc, etc.
But ONLY if you are row 7 and UP. If you are row 6 or lower, the lamps do little to nothing.