Actually during warm spells it's the best thing you could do. Wrapping doesn't always work for it really cannot keep a tree warm. What it can do is keep temperatures constant. If your tree didn't have the leaves, it could have started growing. Many fruit trees are flowering now, which means no fruit next spring. It is the freeze-thaw cycle that hurts a lot of plants. Thaw on a sunny winter day, and freeze again at night. Too many days like that will kill many types of plants.
Where I'm at wrapping doesn't do much good for figs. It's cold, and cold for a long time. Anyway the number of figs that work outside here is low. Burying the fig tree would work, labor intensive though.
So wrapping the figs holds the temp around the plant constant, warm or cold. That is a very good thing in zones like 7a. there it is very helpful to keep temps more constant during the winter.