Winterization is the process of preparing something for winter.
In emergency or disaster response situations, such as managed by the UNHCR, winterization activities include the distribution of items including blankets, quilts, kerosene, heating stoves, jerry cans, as well as thermal floor mats and insulation to make tents warmer and more resistant to harsh winter conditions.
Some summer homes, also known as cabins or cottages, were built for summer use only and need to be winterized each Autumn. This entails locking them up, turning off water, electricity, and phone lines, and protecting various features from heavy snowfall.
In the New England area, many wealthy families living in cities during the 19th century had summer homes in the mountains. This was to flee the onset of yellow fever and other epidemics which often struck in the summer months, when city plumbing problems and stagnant horse manure in the streets caused a health hazard. Winterization would take place each Fall when the families returned to the cities (often when school started). In those days, winterization just referred to a lock-down of all movable parts as protection from winter storms. An example of such a summer home that needs to be winterized each fall is the scene of the movie On Golden Pond, which was filmed on Squam Lake.
In the 20th century, these summer mountain homes in turn were winterized to enable winter holidays, as the popularity of skiing in the mountains increased that of summer camping. In this sense, winterization refers to the addition of modern amenities such as heating and insulation, often entailing a complete rebuild of the cottage.
Equipment designed for use in particularly extreme cold conditions (such as the polar regions) also undergoes a "winterization" process. Many complex devices (automobiles, electronics and radios) as well as common materials (metals, rubbers, petroleum lubricants) are not designed to operate at extremely low temperatures and must be winterized to operate without severe damage from the elements in such conditions. This might involve a chemical treatment process, additional waterproofing/insulation, or even the total substitution of new parts. An example would be the internal combustion engine of an automobile; the installation of heaters on the engine block and battery as well as the substitution of winter-grade coolants and lubricants allows the vehicle to start and run in sub-freezing conditions where a non-winterized engine would quickly break down.