D&D 5E Sleep Deprivation Rules?

[Saeviomagy]

Sleep Deprivation: Most characters need to sleep for at least 6 hours every 24 hours. Once a character has been awake for 18 hours, they must make a Constitution save. The DC is 10 + 1 for each 6 hours past 18 (10 at 18, 11 at 24). On a failed saving throw, a character suffers one level of exhaustion; if the save fails by 10 or more, they fall asleep. While fatigued in this manner, any strenuous activity (an hour of travel at slow speed, a minute of combat or dashing) counts as a forced march and requires its own Constitution saving throws.

I think that by those rules, I've died multiple times since the birth of my first child. And possibly a couple of times prior to that.

Also you can sleep for 5 minutes every 17 hours and 55 minutes and never suffer any ill effects under those rules.

 

[Rya.Reisender]

I do it like this and it worked quite well for me:
- My group can only do a short rest when they fought at least one battle since the last short rest
- My group can only do a long rest when they are tired
- When my group does a short rest and they didn't sleep for a while I tell them that they start feeling sleepy, this tells them that they can't do another short rest, but they can do a long rest now
- When my group then wants to do another short rest, they all have to roll a DC 10 constitution check, if they fail, they suffer one level of exhaustion