I posted something similar to this a couple of months ago. I have a SWCAH daughter who is 5 months old, and for a couple weeks, her hands would be totally white and cold when I woke her up at 11pm to feed her and give meds. It really freaked me out the first time! It also coincided with her urinating a lot, so I thought it could have something to do with a fluid imbalance. I didn’t ever take her temperature during this time (it didn’t happen every night and it resolved itself after a couple weeks) because she always felt fine everywhere else. Her endo didn’t think it was anything to worry about. Now, if she ever feels weird, I take an armpit temp (which is often in the 96.5-97.5 range) and if it’s off I then take a rectal temp.