Jeff Probst weighs in on last night's scary episode of Survivor: Kaoh Rong, which featured in three people requiring medical attention.

Last night's episode of Survivor: Kaoh Rong centered on a challenge that proved much more dangerous than the crew could ever anticipate. Caleb Reynolds, Cydney Gillon and Debbie Wanner were all overwhelmed by the scorching heat and needed the Survivor medical team to help them recuperate.

While Cydney and Debbie were able to recover, the severity of Caleb's condition led to his evacuation from the game.

Probst spoke with Entertainment Weekly after this episode about what went wrong and where this ranks on the list of scariest medical evacuations.

"I wish it was as simple as saying, 'We pushed too far,' because that would be easy to fix. The truth is, we've done that kind of a challenge many times on Survivor and from a physical point of view, it's actually one of the least demanding," Probst said. "Our assessment, upon reflection, was that it was a perfect storm of events—Mother Nature at her absolute hottest combined with a group of players pushing themselves as hard as they could."

The host went so far as to say this was "the most frightened" he's ever been in 16 years of Survivor.

"There was no color in Caleb's face and very little response from him for quite a while. Even for the first few moments after they put the oxygen mask on, Caleb didn't respond," Probst recalled. "Then, out of nowhere, he took a breath and suddenly the color returned, his face filled out again and in a matter of seconds he was back. It was very powerful to witness. I don't imagine Caleb has any idea what he went through and watching the episode was probably very emotional for him and his family."

Survivor: Kaoh Rong - Brawn vs. Brains vs. Beauty airs Wednesdays at 8 p.m. ET/PT on CBS.