15-1. Cold regions include arctic and subarctic areas and areas immediately adjoining them. You can classify about 48 percent of the Northern Hemisphere's total landmass as a cold region due to the influence and extent of air temperatures. Ocean currents affect cold weather and cause large areas normally included in the temperate zone to fall within the cold regions during winter periods. Elevation also has a marked effect on defining cold regions.
15-2. Within the cold weather regions, you may face two types of cold weather environments—wet or dry. Knowing in which environment your area of operations falls will affect planning and execution of a cold weather operation.
WET COLD WEATHER ENVIRONMENTS
15-3. Wet cold weather conditions exist when the average temperature in a 24-hour period is -10 degrees C (14 degrees F) or above. Characteristics of this condition are freezing during the colder night hours and thawing during the day. Although the temperatures are warmer during this condition, the terrain is usually very sloppy due to slush and mud. You must concentrate on protecting yourself from the wet ground and from freezing rain or wet snow.
DRY COLD WEATHER ENVIRONMENTS
15-4. Dry cold weather conditions exist when the average temperature in a 24-hour period remains below -10 degrees C (14 degrees F). Even though the temperatures in this condition are much lower than normal, you do not have to contend with the freezing and thawing. In these conditions, you need more layers of inner clothing to protect you from temperatures as low as -60 degrees C (-76 degrees F). Extremely hazardous conditions exist when wind and low temperature combine.