It has to be 40 or lower and the option must ne turned on.
• Auto-On Driver Heated/Ventilated Seat & Steering Wheel With Vehicle Start — If Equipped When this feature is selected the driver’s heated seat and heated steering wheel will automatically turn ON when temperatures are below 40° F (4.4° C). When temperatures are above 80° F (26.7° C) the driver vented seat will turn ON. To make your selection, press the “Auto Heated Seats” button on the touchscreen, then select either “Off,” “Remote Start” or “All Starts.”"