I've been wondering about this too. I'm still up with DS a few times a night. We are co-sleeping though but trying to get him to go part of the night alone in his bed. Regardless the time of day I'm up in the morning and night time activity is all over the place. From what I remember of my charting when we were ttc it really is important for accurate charting to be able to take your temp at the same time each morning before you get out of bed and for the room temp to be pretty much the same each night and have the same cover on etc. Having said that I think that's pretty extreme. I feel pretty confident that even with getting up a bit you'll still see a big enough temp rise after ovulation to determine when you have ovulated. That is a personal thing too though I guess. I used to see a definite rise the next day but some woman only have a slight one. If you were like that then the up and down during the night and temp changes in room etc would be more important. hope that helps