One of the problems with going past eighty years is that it is common for the fingernails to get thinner, grow more slowly, and get brittle and crack at the tips more easily. This is a slow process, so if you’re twenty years old now you will have plenty of vastly more important things to think about before you encounter this problem.
But I am encountering it, and so I am thinking about how I can solve this little problem. I’ve tried the various creams, coatings, and vitamin pills, and maybe they work but not very well and I still have the problem. Mostly the nails don’t break, but they get little notches that snag on things. I clip them a little shorter most days just behind any notches and no one would ever know that I have a problem, because it’s invisible.
So, what might be the problem? Perhaps the fingernails are not getting enough blood and nutrients to grow with more youthful vigor, and perhaps that is caused by simply having a lower body temperature. Old people typically are a degree or two lower than when they were young; that slows them down, but it also slows down their aging processes. I’m going to check around with my older friends and ask if they are having cold hands and ask them about their fingernails, and if their fingernails are growing noticeably slower than they used to; I know mine are.
My first thoughts on curing this slow-growing fingernail problem were to warm up the hands because if the hands were warmer and the blood was flowing faster, the fingernails would grow better. I thought about various gloves types: the possibilities include getting some electrically heating skiing gloves, and some have microwavable materials that will keep hands warm for a while. There is the possibility of just wearing knit wool gloves which will help if the blood is already warm and flowing. There is the possibility of getting gloves of that type with the palm side of the fingertips exposed but not the fingernail side. That type would keep the fingernails warmer and leave the surfaces of the tips exposed so you could use your fingers more normally. There is the possibility of having single tube gloves for each finger, like socks for each finger. None of those seemed like they could be worn indoors all day and all night
Ultimately the easiest thing to do is to develop the habit of keeping the fingernails warm by curling the fingers closed and when possible to press your curled fingers closed into a fist and pressed them to your tummy. This can be done easily and you can remain in a totally socially acceptable posture. When clothing pockets are available you can place your hands in them and curl your fingers so your fingernails are nearest your warm body.
The goal is to keep your fingernails warm and comfortable, so they can grow naturally.
Probaway - Life Hacks 
Thinsulate slippers and gloves is a miracle in old age where venous insufficiency makes your extremities colder. You want to get gloves with the fingers cut off for indoor use so you can still type. Geezers also often double up on their socks not only for extra cushioning but also extra insulation. In winter, over the head ski masks under your hat also help but don’t wear masks to the bank or you might get shot. Though it gets nippy sometimes in Bend, you likely won’t need these in Florida.
Thanks for your comments R. Lee! I read them every day and they do affect my later posts. Yes, Thinsulate gloves help. Does it strike you as strange that life expectancy is greatest in North Dacota and Hawaii? The coldest and most mildest places in the US. I am now 83 3/4 years old and I suppose that I’m now officially a geezer but I like to say that I’m 83 going on 4. Some of my friends seem to think I am a bit childish, with my unconventional thoughts, but I like to believe that I’m an independent thinker. I’m having a good time, most of the time. How did you like the 4th of July photos?