Are you worried about your plants during these dramatic swings in temperature? Start by understanding the difference between Cold Damage and Drought Damage.
This is when mid-winter temperature swings can damage broadleaf evergreens. The most damage is done in early and late winter, when plants are less acclimated to the cold. This kind of temperature change affects the entire plant.
Winter Drought Damage
In mid-winter, the real damage is drought damage. When we have warm temperatures followed by cold temperatures. The combination of extended below freezing temperatures and bright sunshine a little or no wind, will cause a drought like condition, even in winter.
The trunks and stems of broadleaf evergreens remain frozen, yet foliage is able to thaw due to the sunshine. The result, the plant starts to photosynthesize. Since all the water in the trunk and stems has frozen, the result is that no water moves upward the foliage becomes dry.
What to look for
If the burn is more pronounced on southern or western sides of the plant, here in the Northern hemisphere, you are probably looking at mid-winter drought injury. If the damage is uniform on all sides of the plant, it's more likely that new growth is being killed by a freeze event.
How to Solve
Unfortunately, there is nothing you can do about it now, but try to remember to water prior to any dramatic temperature change in the future. That way, your plants will have the best fighting chance.
Don't immediately start removing damaged stems, as it may take weeks for all the damage to be visible. Rather, take care of any pruning when temperatures have stabilized, usually in late March or early April.
Lastly, remember this weather event on your garden calendar. So, when you see the damage later in spring, you'll remember the event that caused it.