When no one is around to remind them to drink fluids, they quickly dehydrate.  Dehydration is severe and affects the entire body.  It may cause abrupt mental confusion, a drop in blood pressure, increased heart palpitations,
angina (chest pain), coma and even death.

This habit of forgetting to drink fluids begins at age 60, when we have just over 50% of the water we should have in our bodies.  People over 60 have a lower water reserve. This is part of the natural aging process.

But there are more complications. Although they are dehydrated, they don't feel like drinking water, because their internal balance mechanisms don't work very well.

Conclusion:
People over 60 years old dehydrate easily, not only because they have a smaller water supply, but also because they do not feel the lack of water in the body.

Although people over 60 may look healthy, the performance of reactions and chemical functions can damage their entire body.

So here are two alerts:
  1) Get into the habit of drinking liquids.  Liquids include water, juices, teas, coconut water, milk, soups, and water-rich fruits, such as watermelon, melon, peaches and pineapple;  Orange and tangerine also work. 

• The important thing is that, every two hours, you must drink some liquid.  Remember this! *

2. Alert for family members: constantly offer fluids to people over 60.  At the same time, observe them.

If you realize that they are rejecting liquids and, from one day to the next, they are irritable, breathless or display a lack of attention, these are almost certainly recurrent symptoms of dehydration.

Arnaldo Liechtenstein (46), physician, is a general practitioner at Hospital das Clínicas and a collaborating professor in the Department of Clinical Medicine at the Faculty of Medicine of the University of São Paulo (USP).

So spread it out!  DON'T FORGET TO DO IT NOW!
Your friends and family need to know for themselves and help you to be healthier and happier.

It's good to share!  For people over 60

I do not know how true it is but it does remind me of the story of the two old men sitting on the park bench when 90 year old Ethel shambles past on her walking frame totally naked. George nudges Kelvin & says "look there's Ethel" and he replies "yes but wouldn't you think that she would have had the decency to iron her dress?"

Further enquiry has turned up the even more disturbing information that only a small loss of water can dangerously affect mental acuity:
[thoughtco.com]