GRAND FORKS, N.D. — You see them crouched alongside northern buildings like horses huddled against the icy wind: cars, vans and pickups with electric tethers running from their engine blocks to outlets mounted on the outside walls of homes, apartment buildings, offices and motels.

It looks funny, all that hitched horsepower, until the air temperature falls below zero as it threatens to do this weekend.

If you make it to the coffeeshop or wherever Saturday morning (when the low is expected to be well below zero) because you plugged your car in last night and — hooray! — it started, you can thank the late Andrew Freeman and the bitter cold of winter in Grand Forks, which challenged Freeman's entreprenurial spirit. Freeman was manager of Minnkota Power Cooperative in Grand Forks and a champion of rural electric cooperatives. He also was stubbornly inventive, and in 1945 he grew impatient with a big V-8 Ford that sometimes balked at starting in subzero weather.

Tinkering in his basement, he worked some scrap hoses and copper tubing onto the heating element of an old flat-iron and produced the first headbolt heater, which warmed the engine's water jacket and the oil film between cylinder heads and pistons. He hooked the contraption to the Ford, waited a bit and — with the temperature about minus-25 degrees Fahrenheit that morning — the engine started right up.

Soon Freeman was fashioning block heaters for his neighbors. "I made them by hand for friends, including my barber," he said in a 1979 interview with the Grand Forks Herald.

In 1947, with patents in hand, he opened a manufacturing plant in East Grand Forks, Minn. Four years later, the company was selling nearly a quarter-million heaters throughout the northern half of the country and Canada. No longer did a motorist need to shovel hot coals beneath a car's engine, douse it with hot water or drain the oil and store it indoors overnight to ensure a quick start in the morning.

The company eventually was sold, and the headbolt heater evolved. Variations became standard equipment in new cars in cold climates around the world, and electrical outlets began to appear on posts in public parking lots and outside motels. (The plugs dangling from cars' grills sometimes confused drivers visiting from warmer climates. "Electric cars? Nice. But don't you need an awfully long extension cord to go anywhere?")

Freeman died in January 1996, at the age of 86. It was cold in Grand Forks then — surprise — but it's commonly assumed that nobody missed his funeral on account of a car that wouldn't start.