Help!!

Last week My ds had started sleeping through the night after a week of his one night feed kept getting later. We had gotten 3 nights in a row. Then on the 4th night he spiked a 100.7 fever which lasted for about 36 hours. since then hasn't slept well at night at all.

Most nights we can initially get him down but once he wakes up we cannot get him back down in his crib. He will be completely asleep when we put him in his crib he wakes up before we even finish getting our arms out from under him. Or if we do get him down it's not for long.

He will be 5 months on the 27th is this a sleep regression or what?

Anyone have any suggestions? Also now that it is warmer out we can't get his room down to 71 like it used to be its now at 74. We have him in a single footed light pj. He doesn't feel warm to the touch.

Due to my husband working 3pm till 6pm and I am up at 4:30 am for work my husband is the one dealing with this. With my mommy instinct I'm not sleeping well either.