During the winter, evergreens can be susceptible to winter burn. This is when the tips of their needles turn red or brown, or just fall off altogether. It occurs for a variety of reasons—one due to the large temperature dips in the evening, leaving the tips to freeze. Another reason is because of photosynthesis. Evergreens will gather energy then release water. If unable to replace that water due to the ground freezing, winter burn can occur. To help avoid this, you can water your evergreens in the winter.
For your evergreens and other trees in your lawn, consider adding an anti-desiccant to them. This is a spray for their leaves that will help them retain water as the temperatures drop.