Many conifers suffer from desiccation of shoots in winter rather than from direct thermal damage.
When the injury is severe, all the needles and buds are killed. Usually, however, the buds escape severe damage. Damage always occurs when water loss through transpiration is greater than water uptake. Bright, warm sunny winter days, especially if they are windy, the temperature above freezing, and the soil frozen, increase the vapor pressure gradient between leaves and the air, causing water to be lost at a high rate. Wind exacerbates the problem.