Whether the change in your baby's sleeping circumstances is permanent (as in the case of a move from one house to another or from one room to another) or is temporary (as in the case of a vacation or a night spent at Grandma's), he is likely to be fearful at first. Honor his fears to a point. Don't let your baby use the change as an excuse to get used to being up late or sleeping in your bed (if you don't have a family bed).

You may need to stay with him while he falls asleep, even if you don't usually do that. You may need to hold him or rock him, things you might not normally do. You may need to make some other type of accommodation. But if the change in his sleeping circumstances is permanent, you need to return to your old discipline within a few days. If the change in his sleeping circumstances is temporary, you need to return to your old routine as soon as you return home.

If you let him, your baby will take advantage of your leniency and continue to insist on your staying with him until he falls asleep or whatever other accommodations you have been making during a vacation or immediately after a move. Without being cruel and lacking understanding, you need to exert discipline and return him to his regular routine.

If your baby, who was sleeping through the night before the vacation or move, continues to wake up during the night even after you return home or after he has had time to get used to the new surroundings, it may be that he's having bad dreams. He may be dreaming of being lost or abandoned. Soothe him, but then put him back to bed in his own crib. Honor his fears, but then be firm. Show him you're there, he has not been abandoned, and it was only a dream, but then put him back in his crib.