MM possibly teething but maybe change i nthe temperature etc? i know that always affected ds1 really badly.
we have been really strict with a bath and bed routine right from the start with both of them - it goes something like this:
645 run bath and bathe sam. jacob runs around like a maniac whilst i do this
700 get sam dressed for bed and in sleeping bag, then give milk (attempt to get 210mls or more into him). while feeding him put jacob on toilet and then into bath, and carry on feeding sam in bathroom...
this goes on till about 715 ish then sam normally finished milk and burped, by which time jacob is out of bath and running around again like a maniac...
730 jacob in bed with bottle of milk and nightlight on.
732 flick is downstairs pouring the wine
MM once you do it a few times they get used to it - sometimes i put in some massage with oil for ds2 which he really likes! i find that a really deep quite warm bath helps to use up all their last energy