You may want to just cover with a little mulch. I saw one of my Holland tulips sprouting about an inch the other day, but just covered it over with some surrounding mulch. With the crazy weather we've been having in Chicago, it's no wonder the plants are confused! Better to keep them insulated now than run the risk of frost damage...

Instead of mulching in the middle of winter which will only trap the cold in at this point (since the ground is frozen), use a cloche instead....that should protect them well enough...