Come up with an escape plan. If for some odd reason your house isn't safe to stay in, you'll need to get out as soon as possible. With your map in hand, get out and get out now. Would you do best in the forest? Near water? Are you concerned with privacy and hiding from others or is there not another soul in sight? Your specific situation will determine where you should go.
When searching for immediate, short-term shelter, look for trees (especially fallen trees), rocky overhangs, and caves. Trees are an obvious source of shelter and have many useful parts for building shelter including the trunk – which can be used as a support, the branches – which can be used as framework, and foliage – which can be used as insulating material.