How can I stop my mother from sweating at night?

What's her body temperature? Are you sure she's not running a fever?

I have our air conditioner set at 79 degrees and my mom is often cold, her hands and legs sometimes feel like ice, but sometimes her body feels warm and she still complains of it being cold. A little bit of a rub to help the circulation shows you are trying to take it seriously, but sometimes I just have to remind her that the house is warm enough and that she will just have to snuggle in and bear it until she can fall asleep. Also, modern electric blankets will turn off after a couple of hours or a hot water bottle tucked against her belly or at her feet will warm her up and cool off slowly.

I know this sounds odd, but do you think she is really cold or her mind is saying that she is cold due to dementia? It could be a delusion. Apparently, her body is hot and that is why she is sweating, unless there is an underlying medical condition.

I'd have her doctor check for the cause of the sweating and feeling cold. It can be a symptom of a medical condition like thyroid problem.

Oh, I might also examine her diet. I know that once when I was eating very little food and losing weight, I stayed cold too. Along with having doctor run tests, I'd ask about increasing her calories, if she isn't overweight.

The secret, wear socks to bed if one is cold. Otherwise, too many bed clothing and too many blankets would make someone sweat during the night.

Sometimes for me, I have found if I am laying down for the night, I will develop acid reflex which will make me feel like I am having a hot flash. Tums help, plus sleeping on two pillows.

I had the same problem with my husband..he would wear a coat or sleep with the blankets on when it was 90 degrees. I tried to explain the reason he felt cold was the sweat was trying to cool off the body but he felt cold because of it.
I have learned many things in this journey but the first is NEVER argue with someone with dementia. You will not "win" and you both end up frustrated.
There are sheets and PJ's that wick away moisture that might help.
Hand warmers and foot warmers might make her feel warmer.
A little stocking cap at night might also help.
Try to get her to drink plenty of fluids, dehydration can also make you feel chilly and if she is sweating a lot she needs to replenish the fluids. Might even want to do a Sports Drink once a day. (if it is something she can have)
All in all if her body temp is alright change the sheets, the clothes and don't worry about it. Next time you bring her to the Dr. you might want to discuss it.
But you probably will not be able to get her to stop bundling up until she declines a bit more and you have more control of clothing, bedding and the like.
I have found with each problem, sometimes the solution comes with a decline and that brings another problem. So I have learned to be thankful for the little problems as larger ones come.

When she says she's cold, have you felt her skin? If not, next time she complains of being cold, feel to check it out for yourself - if this is real or a delusion as Sunnygirl suggested. Especially feel her feet. If in fact her feet feel cold she could have a circulation problem which may be related to a heart condition- unless she already has been diagnosed with one? Regardless, it does seem worthwhile to schedule a dr appointment given all the disruption this is causing. I imagine you are doing laundry non-stop, not to mention sleep deprivation!

Have her thyroid checked. My Mom was always cold and anything she touched was ice cold. An adjustment was made in her medication and now she is fine. Also alcohol will make you sweat and if she is imbibing late at night she will sweat in her sleep.

My 90+ mother was always cold until we gave her something alled "VitaPulse". Not sure why that worked but it did (has CoQ10, NAC and PQQ in it). Choline helps with mental clarity. We always kept socks on her. Maybe gloves and a hat would work better than more blankets. Every person is different.

Maddycat hits the nail on the head. You did not metion your mothers age but I am 56 and healthy and I am experiencing the same symptoms. It is the hot flashes and night sweats of menopause.