I have that vest your looking at and for 2 years now it has continued to work with no problem. I use mine while riding my Harley during the Winter months to break off a bit of the 75-80 mph wind chill. These types things can be expensive but what ever your price range is just make sure it has an adjustable heat setting. What may be warm to you might feel scolding to me and so forth. If he still moves around good in the cold just over insulate a box stand and invest in some quite sliding windows. There are many options for comfort but like you say it will have to meet his approval personally or it could wind up being a waste of effort.
If you don't understand the technology which you depend on, you will soon be a victim of that technology.