Ten hexes north, four northeast of Alakran.
Let's take a detour into these unremarkable hills, far from the footsteps of adventure, to talk mechanics for a minute.
It's an irony of the Fifth Edition of the world's most profitable roleplaying game that, many times, taking a long walk in the hot sun is going to have more long-lasting consequences than being damaged past the limitations of your frail body by a titan's hammer, a dose of poison, the fires of spellcraft, or any other source of damage.
Yes, as long as damage does not outright kill you by taking you to negative hits at or beyond your starting amount, no matter how far beyond zero you've been knocked, you enter a game with death - one that you're tipped to win. But usually, a well-prepared party will have some kind of healing that can be thrown on an unconscious colleague to instantly bounce them back to positive hp. Just take a half-move to get up.
Now, I value a system with some grievous consequences for violence -- it leads to more thoughtful and exciting play. For me, the bouncy combat in my Band of Bronze 5th edition campaign sometimes strained credibility. When the campaign entered hot summer months in the desert, I started applying the exhaustion rules, but found that they hit much harder than any mere damage (such as my 52 Pages rules apply, one hit point per level, for exhausting conditions.) You may not want to send your skill-heavy character adventuring after even one (disadvantage on skills) or two (half move) levels, and at three exhaustion levels they get disadvantage to everything. Further down that road lurks immobility and unavoidable death.
Amazingly, exhaustion in 5e is immune to just about any restorative effect and requires good old bed (long) rest -- one per exhaustion level -- to get over. These are serious, but not disastrous, costs to the pace and effectiveness of an adventure. So, in my new 5e campaign -- set in a wet, chilly, forested land diametrically across the surface of the campaign world -- I applied them to zero hit point situations as follows:
· When a character is healed above 0 HP or succeeds a third death save, they gain 1 level of exhaustion, plus 1 level for each death save failed for any reason (including taking damage) while at 0 HP.
Looking at the rule in practice, though, it gets simplified more often than not to "1 level per death save made for any reason" -- which means the exhaustion hits harder and more often, but a character knocked down and quickly healed can get away with little penalty. As long as it only happens once. For the dramatic and grueling bleedout of a death save sequence, exhaustion is a fit consequence. I also decided 5th edition needed more consequences for blows that take you way below zero without outright killing, and I will share those at the next rules-related rest stop.