Is there any way to prevent damage to bulbs that have peeked through with this warm weather? Sure don't want to miss them next spring. Mulch, or leave alone?
I had this happen a couple of years ago with daffodils. I actually had one of two to bloom. I just left them alone and they still came up in the spring. Others may have more sound advice for you.
In other years I've had a few "early birds" get confused during a warm break. I just leave them alone - they seem to bloom in the spring without any trouble. If they're in an exposed spot I might pat a little extra mulch around them, if I think about it. Otherwise, they just have to fend for themselves.
My grape hyacinth actually start growing again this time of the year. Some even stay green all winter long. But they do bloom in the spring just like they should. I think they just need to stretch their legs from the summer break.