Normal body tempature?

Hey I was just wondering...for a person is 91 a low tempature like is it unhealthy because my sister just came in and said that was her temp and shes freezing and she has an eating disorder and I just am making sure that shes okay...

If your thermometer is correct, that is definitely a worrying low temperature. There can be many causes - but really, you should get in touch with a qualified doctor, right away.

(You might just take your own temperature first, with the same thermometer, to check whether it's way off...)

if her temperature was that low (91) she would not be able to function, the temperature where hypothermia starts is around 94 or 95, so I would say your thermometer is a little bit off.
at 91 her skin would be pretty blue, and she would be shivering non stop, and most likely huddled up somewhere trying to warm up.

I STILL say, contact a doctor! As baldwinwolf says, that's below the usual hypothermia limit. Things are definitely NOT GOOD.

In the meantime, try to get her warmed up. Maybe a hot bath (if your bathroom is warm), but the best remedy is simply to get under the covers with her and hold her tight. And no alcohol!

Well, first of all, you're speaking in terms of Farenheit, right? If that's the case, 98.8 degrees is normal. She's freezing, but her temp is 91?! Are you cold as well? Unless you both are in a cold place or did she JUST come in/ out from one? If not, then this could be a symptom of shock! I'm trained in first aid, so follow my advice: Call 911! Then, ask her to lie down, make her rest her legs on something like a small box (raise her legs about 12 in. And keep them there), and put a blanket or something similar on top!

 
You said she has an eating disorder. Accordingly, if she is underweight, her body may not have the reserves to maintain normal body temperature and could be in the process of shutting down. She should definitely see a doctor immediately. She is in danger.

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This is much later, and I do hope things are better.

After I signed off, I realised I should have added: get her to sip some hot soup.

Nothing greasy or lumpy, simple tomato soup. Even with an eating disorder, that shouldn't be too hard. Sip through a straw if that's easier for her to manage. The shower (a bath would have been better) can help, but her insides need warming up too.

And never never alcohol when anyone is chilled down - d'you hear me, out there?