Temperature fluctuations increases the risk of sunscald. Damage will show up as splitting of the trunk. Trees in a south or west aspect are subjected to bright winter sun and are most susceptible.
Evergreens dry out by moisture loss through their needles. As needles can both absorb and lose moisture spraying foliage is also helpful.
Prevention: water everything well before the soil freezes. Trees need deep, thorough watering. This will provide a buffer to the drying effects of winter.
Leaving leaves and or mulch around plants will act as a insulation to fluctuating temperatures and trap snow/moisture around your plants.
Wrap trees especially bronze-coloured bark trees with tree wrap kits or materials available at hardware stores.
Evergreens in a south or west aspect may benefit from a temporary shade structure to protect them from the bright winter sun.