What if you’re in hell and u r mad at this person who is also in hell so where do you tell them to go??? 
Re: What if…
If you are in hell, you will not really be in a situation to tell anyone anything. Nafsa nafsi ka alam hoga :no:
So to come back to your question, first figure out if you are in hell because of that person. If so, then you need to say goodbye to that person and move on.
Re: What if.....
Depends which hell you're in, there are levels of hell, so i guess you t ell them to go to the very bottom :?
Re: What if.....
^ Yes exactly. And if you are in the bottom already, then tell him to go a level up, so at least he is out of your sight.
Re: What if…
hell is a very bad thing to wish on someone
may ALLAH SWT keep us safe from hell 
Good Answer
But ask for Allah(SWT) mercy from Hell. The very very little sample of Hell is Sun, just imagine if one is thrown on the surface of sun & that one is not allowed to die, ever …!
lol..
Didn’t you just ask people to assume they were in hell?
it could have been written:
I wonder if I were in hell and…
Anyhow, madness for other may even become ground for hotter temperature!
So avoid being mad at someone even in hell.
Its not cool to be mad at someone! (Pun intended)
Where is philosophy behind this kind of question