EV’s are notorious for losing range in cold weather in part because energy that would otherwise be used to propel the vehicle forward is instead diverted to warm the vehicle cabin. Prototype “heat belts” (oh I get it, a pun) from ZF could help eliminate that thermal waste by using the same principle as an electric blanket.

Essentially, instead of trying to warm all of the air in the cabin, ZF’s 70W heat belts warm up just the front of the driver’s torso and pelvis. “In combination with heated seats, the heated seat belt has the potential to provide occupant comfort quickly,” wrote ZF’s Andreas Neemann on Wednesday. “Reducing the amount of battery current used to heat the interior of the vehicle, may enable a range gain of up to 15 percent.”

The seatbelts conduct heat because they also conduct electricity through tiny heating elements woven into the belt’s fabric. The company asserts that these elements will not impact the seat belt’s crash performance, and both feel and look identical to existing belts. Unfortunately, details are scarce beyond that. The company has not revealed how warm they get, when they’ll be available or on what vehicles.