At Total Temperature Control, Inc. our high standards for quality means that our customers can rely on us to use premium products, supported by topnotch service. That’s one of the reasons John has been certified by NATE. North American Technician Excellence, Inc. (NATE) is the leading certification program for technicians in the heating, ventilation, air-conditioning, and refrigeration (HVAC/R) industry and is the only test supported by the entire industry. To be certified by NATE means that you meet the highest standards the industry has established.