If I were the Heat, I would file a formal protest.
I'm the farthest thing from a Heat fan on the face of the earth, but that was fucking bullshit. Given the Heat's heavy reliance on LeBron, Bosh and Wade (and their collective ability to play high minutes), the heat issue disproportionately impacted them. Where the Spurs have such a deep bench they could give everyone 20 minutes and still produce wins, the Heat can't do that and win. Their bench is far less reliable, and the Heat's "big 3" typically represent 70% or more of the scoring. In general, the more minutes you play, the more fatigued you get...but tonight, it was fatigue squared.
LeBron was probably suffering from heat exhaustion. What he needed was an IV. You can't drink away heat exhaustion and cramping of that type because the stomach has to absorb the liquid before your body gets access to it. Their team doctor should have been on top of that shit and honestly, he shouldn't have a job if he couldn't recognize that or see it coming before it happened.