The recent changes in your mother's behavior sounds concerning. There could be a number of explanations for this change, so it is imperative that you speak with her physician. There may be some medical reasons why this is happening, so further assessment and evaluation is necessary in order to rule out possible causes, such as depression, vitamin deficiency or thyroid imbalance, for example. You can also use this time to discuss with your mother's physician any possible medication changes that might be in order. It is important to know that as dementia progresses, the brain deteriorates in such a way that judgment becomes impaired. Inhibitions are lowered, as is the ability to process and understand social cues and mores. Because the person with Alzheimer's disease loses the ability to verbalize their thoughts or feelings, they may act out their feelings physically. Other individuals can become so frightened of their surroundings that they become aggressive as a way of protecting themselves. Aggressive outbursts are not uncommon for people with dementia. If considering long-term care, it is important to consult with your mother's physician for a full assessment of her level of needs and to share your concerns for her safety to determine where her needs can best be met.
Her doctor needs to know about this. There could be a medication that may help, or she may be taking one that is making her symptoms worse. However, it does seem that her behavior is getting pretty drastic. You may need to look at a nursing home, if she won't let her current caregiver help her. This is about her safety.
Carol is right, if you cannot afford 24 hour home care and the caregivers cannot convince her to put on her clothes, you need to get her into a nursing home for memory impaired so she would not get lost and wander in the cold without any coat. The specialized home will know how to handle this kind of thing.
A confined unit can make sure she is safe without wandering. She can wear comfortable clothes and etc.
There are some possibliities about this behavior. First of all, it is quite common for the elders with dementia to be unaware of dress code and take off the clothes in public or in private. She would not know this is not proper anymore. This is usually in moderate stage. Either she does not know how to get dressed and refuses to be dressed or she is very warrm and does not like it but does not understand she cannot be improperly dressed. You can try to give her casual clothes instead of formal clothes as well as the ones that are easier to be put on.
My father-in-law has late Alzheimer's. For the last 2 or 3 summers, he always rolled up his t-shirt above his chest/nipple to get the suntan not knowing it is not quite "proper". He used to be quite proper before he got sick. Since he is a man, the caregiver just let it be because he would not let anyone to roll it down or he would roll it up again because he was hot. He has trouble getting dressed and would put on a shirt inside out and etc. He does not know how to use buttons or zippers anymore. Now he is dressed by the caregivers.
Depending on how much clothes she took off - if she took off too much, make sure the room is warm and give her a throw blanket in case. If it is about the style, get a casual one that is easier to be put on - the ones without zipper or buttons... Use elastic waist band for pants or shirts.
She may not need to go to a nursing home. It all depends on how the caregiver can convince her to put on her clothes. You can try to find out why she took it off - is it because of frustration or because of heat... She may be cold because she does not understand the temperature.
She may also need 24 hour home care now. The issue about nursing home is not so simple. It depends on your expenses and her sickness. My FIL waited until mid stage 6 (he had eating problem) to be moved to a nursing home last summer. You have to consider many factors. Taking off clothes may not mean the need of going to the nursing home. Have you tried to hire a home care service? Some company has experienced home care nurse who knows dementia and they can tell you how to cope with it. One has to be nice to her and no one can irritate her.
Hope this helps,