Today, we take for granted the fact our car will start right up on those sub-zero days. For the most part, the only thing we care concerned with is that the battery has enough cold cranking amps to get the engine to turn over, not weather the engine will be hot enough to run. Thanks to electronic fuel injection we don't have much to worry about, the engine computer takes care of everything. In the earlier days of motoring, however, life was not so simple.
The biggest hurdle when starting a car in the cold is that the engine is well below operating temperature. The metal block is so cold that ignition may not be able to be properly sustained under such harsh conditions (remember, there is no electronic control, only mechanical control). To get the engine to operate properly, it must warm up a bit first. One way to do this is to minimize airflow into the radiator to prevent the coolant from dropping in temperature when it needs to be warmed up.
Since most cars just had an open radiator grille, something would need to be placed in front of the grille to limit airflow in the cold, at least until the car warmed up. Enter the Pines Automatic Winterfront. Pines was a company in Chicago (which, by the way, had anoutdoor temperature of 13 F/-10.6 C last week) that built a special grille that could be affixed to the front a vehicle to help it warm up in the cold. The grille had opening and closing slats that were regulated by a thermostat that monitored the temperature of the coolant. When the coolant passed 130 F, the slats opened up. Conversely, when the collant temperature dropped below 130 F, the slats would close. Some less expensive models produced by other companies were simple solid metal that had to later be removed to prevent overheating.
More expensive cars, such as Auburns, Duesenbergs, and Rolls-Royces had a similar system built into the grille. If you look closely, the grille slats on all of these cars could swivel, opening and closing automatically (based on mechanical regulation) to maintain the optimal operating temperatures in the engine.
Today, you rarely ever see a Pines Automatic Winterfront on a car since nobody drives their old cars in the winter (too much salt and grime, all of which is bad for the metal). As a garage novelty though, you can often find an old Pines Automatic Winterfront hanging in the garages of many collectors.