I live in a city in which it is below zero 8 months out of every year.
I live with Eskimo's in the upper Arctic of Alaska - the city is Barrow Alaska.
temps can plunge as low as 50 below and colder !! I have used more than a dozen different types of cameras over a 30 year span.
My camera(s) sit on a tripod outside for two months! IN the most brutal weather immaginable.
For two months every year - the village(s) move many miles out on the ocean ice pack of the Chukchi Sea. This is where we hunt for food.
I have been 'active' in over 70 different forums on PHOTOGRAPHY. Every forum has this same exact question; The answers are pretty standard.
Use a bag to insulate your camera before you bring it in to the warm (area) such as a house.
In 30 years time; I have NEVER DONE THAT !!
I take the camera (as shown) and bring it directly into the house; I place the camera on a table; then I get an absorbent towel to place the camera on - and I let the condensation process BEGIN.
I prefer to call it - "sweating" because as I wipe the water off the camera, it sweats some more - and continues to do so for many hours.
This is a time well spent - cleaning the camera!!
Under no conditions do you ever open the back or remove the lens; until the process has run its course.
I began documenting the Inupiaq way of life in 1981. I used 100 rolls of film the first year & 500 rolls of film the next year. I processed ALL COLOR FILM - by using SNOW as I had no source of water.!!
I am happy to say; not once in 30 years have I had a camera malfunction.
ALL of my film is still in pristine condition 30 years later!!
My favorite camera to use is a studio camera; it is a mechanical camera; which requires no batteries. MAMIYA RB 67
My cameras become encased in ice and they still function.