During WW2 the Willys MB and Ford GPW “jeep” were used over the entire world. Most of the time they were used as open vehicles. But in some extremely cold climates the jeep was equipped with heaters and full enclosures to protect the crew. This book covers the winterization gear used on the jeeps.
When I was in Alaska, I used the Hood and Brush Guard Blankets to protect my engine from the extreme cold during operation. It was very effective. At extreme cold temperatures below -45°F, I would leave the brush guard opening closed (only the light closures would remain open.) Sure made a difference in engine operating temperature and how well my heater worked.
The book is available from Amazon.com and other fine booksellers.
Winter & the MB/GPW