November 7, 1940, Winnipeg Tribune (source)
Here's a test to see how old you are: do you remember car window frost shields ?!
For those that don't, they were rectangles of plastic with a raised adhesive strip around the entire edge. You stuck them to the inside of your car windows and they prevented condensation from forming and becoming frost. If you want to get technical about it, here's a 1941 patent for a frost shield that explains how the work in excruciating detail !
The first winter: November 25, 1926, Manitoba Free Press
Soon a way of life: October 24, 1952, Winnipeg Free PressFrost shields burst onto the automotive scene in the winter of 1926 - 27, long before front and rear window defrosters were a gleam in the eye of automotive engineers. They were soon a standard part of your basic winter tune-up, along with radiator grill covers and winter anti-freeze.
The first shields were actually a thin piece of glass that came with a rubber gasket and a jar of adhesive. It wasn't until the late 1940s that celluloid versions were advertised. Soon after, there were electric versions that used heated wires running through the glass to keep them frost free, (see the image of the Stearn's electric frost shield below.)
November 6, 1948, Winnipeg Tribune
November 30, 1955, Manitoba Free Press
In 1937 it became law in Manitoba that your windshield, rear window and front-row side windows had to be fitted with frost shields from December 1st to March 31st. The law was updated a number of times to tinker with the size and placement of the shields. When spring came, the car owner had the unenviable task of trying to remove what was left of the shield and its adhesive residue.
As windshield defrosters became more commonplace in the 1950s and rear window defrosters in the 1970s, the demand for frost shields diminished. You might be surprised to know, though, that their use is still mandated in Manitoba's Highway Traffic Act:
Frost Shields Required
57(2) The windshield, rear windows, and windows at both sides of the driver's seat, of every motor vehicle at all times between the first day of November in each year and the thirty-first day of March next following, both dates inclusive, shall be equipped with adequate frost shields of a size and type that will prevent or minimize the condensation thereon of moisture in the atmosphere and allow the driver to have a view sufficiently clear and unobstructed to permit him to operate the vehicle with safety to other persons and vehicles on the highway, unless the vehicle is otherwise so equipped or constructed as to secure a like result.
November 24, 1959, Ottawa Citizen (source)
As you might suspect, Winnipeg was a hub for the manufacture of frost shields.
Until 1934 frost shields were imported to the province, mainly from the U.S.. That year, the Electric Heating and Manufacturing Company of Winnipeg showed off their patented Ful-Vue Glass Automotive Frost Shield at the Industrial Exhibition.
In the mid-1940s there were at least four companies that made them. James B. Carter Ltd. (above) was likely the largest and sold them across the country. Through various mergers the company became Temro Phillips which still manufactured car interior heaters in Winnipeg until the plant was closed in 2012.
April 10, 1962, Winnipeg Free Press
In 1951 Del Richardson purchased the name and equipment from the defunct Stearn's Automotive Products of Minnesota and set up shop at 666 Arlington Street. Within a decade they were selling frost shields around the world and considered themselves the largest manufacturer of the product, anywhere. In 1962 the company moved to larger premises at 92 Gomez Street to keep up with demand.
In case you think that frost shields have disappeared into history, they haven't. They are still used in construction equipment, helicopters and out-buildings. The only company I could find that still manufactures them is, of course, right here in Manitoba. Check out Custom Tarps and Filters in Brandon !
Stearn's electric frost shield from ebay
Stearn's frost shield for Mini Cooper from ebay