I find my DH washing his hands in too hot water in his bathroom. I keep the water heater at 120° for laundry and the dishwasher. I wonder if anyone has had any experience with touchless water faucets that you can set the temperature under the sink so it always comes out the same temp. Do you then have to brush your teeth with warm or hot water. I need to know more about how they work before I invest in one. They are recommended by the Americans With Disabilities.
https://www.alzstore.com/anti-scald-device-p/0200.htm
https://www.alzstore.com/complete-guide-to-alzheimers-proofing-your-home-p/2149.htm
Just an idea, anyways
Simply turn off the hot water handle (or turn it down low) under the bathroom sink where he washes his hands, so he can't burn himself.
I wouldn't worry so much about finding the precise temperature for hand washing. He can wash his hands in cold water.
Your husband has dementia. There are many things you are not going to be able to control, and you are going to learn to compromise your usual standards.
Google those two terms in quotes and there should be a number of instructions on how to do it. Might only take just a few minutes of time to solve the problem.
I have a question. In your profile, you say, "He generally goes in the bathroom to prepare for bed about 9PM and stays there until anytime between 2AM and 7AM. I get him up by noon to have breakfast and then he sometimes falls asleep in the afternoon or watches TV or reads until 9PM. Then back to the bathroom."
I've read this several times. Are you saying DH stays in the bathroom from 9pm until between 2am and 7am??
I take over those jobs on the weekends and he mostly complies because his Nurse told him to. We have him on a two hour bathroom schedule. I accompany him and help change his pull-ups if necessary. The problem arises when I get busy with chores, preparing dinner or take a needed nap and he decides to use the bathroom between scheduled times by himself. I am trying to make it as safe as possible for him.
I am not ready to place him in care!!!
But a quick and easy fix...
Get some bright red nail polish and paint a stripe on the faucet handle and line it up where it should be when the water temperature is where it should be. That should give him a visual cue as to where the faucet should be. I say red because red is often associated with STOP or DANGER so this m ight work.
To your thought about the infrared faucets. My Husband with dementia could not figure out how to get the faucet to turn on. All he had to do what put his hands under the faucet but he kept looking and grasping for a faucet handle.
So it depends on how your husband will catch on to the touchless one. I would hate to spend a lot for the faucet and the installation to find he did not know how to use it.
The touchless are like any other faucet the water will come out the temp you set. It might take a few minutes to get the warm water just like it takes a while to get the water that is in the pipes out and the water from the water heater to the open faucet. The touchless ones do not heat at the point of the control the water comes from your water heater in the basement or where ever it is.
From what I gather after reading your profile, your husband is pretty good natured and so far easy to get along with in his disease, so not sure I'm understanding why this is an issue. I mean at least he's washing his hands right?
As far as the touchless faucet that you can set the temperature under the sink, I haven't a clue about that, but what I do have a clue about is that when dealing with someone with dementia, it is best to pick your battles wisely, as all are not worth fighting.
Wishing you the very best as you travel this difficult journey with your husband.