I didn't know the latin name, but I already knew the principle. That's why I intuitively tried to force-drink while at a staffed control in a town, so help would be at hand.
Hyponoeutria is where you’ve drunk too much, compared to salt intake. Thus the answer is not to force more water down, but to get salts on board. I’ve also been there during my travails in the heat.
Having said the above I’ve still suffered from heat exhaustion when I’ve done everything right with drinking and salt replacement etc. Some of us, and I count myself among them, just aren’t built for prolonged exercise in the heat. The only answer is to stop exercising and get out the heat as best possible. Sometimes that means abandoning events for the sake of your health.
The cold and wet on the other hand, I deal with very well, and these conditions have never been a cause of concern for me, or resulted in a DNF.