Speaking of exhaustion, I think some of us give in to POIS too easily. At least I do.
When POIS hits, I "freeze" and do NOTHING - - - as much as possible of nothing!
The other day, I was at Day Zero, and I drove 11 hours and interacted with my son while driving (he asked ME to drive!) and after I dropped him off midway in a surprise hailstorm (!) I....got lost!
I proceeded to drive with my iPhone GPS (dangerous as hell, I will admit), somehow managing to continue to get lost regardless.
By the time I reached a restaurant at night, my anxiety was sky-high, so I proceeded to stupidly and almost unconsciously...BITE my tongue, harder than ever! I was bleeding profusely, my wife AND the restaurant suggested I go to the ER at the hospital nearby.
I decided to tough it out and drive home. Saw the doctor the next day, who said I will heal in 10 days, no infection, but if I had gone to the ER, they would have stitched my tongue.
Now this could have easily happened out-of-POIS.
My main point to you, the reader, is that you CAN do things in POIS, don't give in to The Monster who says, "Die, please, till POIS passes".
If someone told me I would go through all that in Day Zero, I would have said, "No way!"