“Sometimes in medical evacuations, you might see a cameraman in a shot but that’s it,” he said. “This was a definite ‘break the fourth wall’ where you don’t pay any attention to where the cameras are. The story, while it’s also important, was such a second-class consideration.”

Mr. Probst said that the three contestants all had heat exhaustion, and that Caleb’s condition was “very serious.”

“It’s easy to say, you guys would love the drama,” he said. “But the truth is, I’m much, much happier when we haven’t had any interaction with our medical department.”

In 2009, another contestant, Russell, collapsed to the ground in an episode that Mr. Probst had previously called the scariest he had witnessed as host.

In a conversation I had with Mr. Probst last year — for an article about the surprising stability of “Survivor,” which remains the most-viewed show in its time slot — he said that the incident with Russell was so terrifying that he was ready to quit the show.

“It definitely rocked my world,” Mr. Probst told me then. “I was holding his head when his eyes were rolling to the back of his head. And I said: ‘Man, maybe I’ve lost my way here for a second. I need to get out and let someone else carry this show.’ ”

When I read the quotation back to Mr. Probst on Thursday, he said that the incident with Caleb was even scarier, but he didn’t feel the same way this time.