During the trial it was revealed that McDonald’s knew that heating their coffee to this temperature would be dangerous, but they did it anyways because it would save them money. When you serve coffee that is too hot to drink, it will take much longer for a person to drink their coffee, which means that McDonald’s will not have to give out as many free refills of coffee. This policy by the fast food chain is the reason the jury awarded $2.7 million dollars in punitive damages in the McDonald's hot coffee case. Punitive damages are meant to punish the defendant for their inappropriate business practice.
82-88 *C, according to the Wikipedia page for the Liebeck vs McDonald’s case. McDonalds also serve their hot coffee in paper cups. I’m not a materials expert, but I have to think paper wouldn’t dissipate that heat as quickly as ceramic.