Jamie Dornan's friend is reflecting on their terrifying encounter with nature.

During a recent episode of The Good, the Bad and the Unexpected comedy show, BBC broadcaster Gordon Smart detailed an experience where he and the Fifty Shades of Grey actor came in contact with poisonous caterpillars while on vacation in Portugal. 

As Gordon explained, he and Jamie were playing golf on the second day of the trip when, "I started to feel tingling in my left hand then tingling in my left arm and as the son of a GP, this is normally the sign of the start of a heart attack."

And although the journalist considers himself healthy, he still decided to get checked out at the course's medical center, where his heart began racing. With the nurse's recommendation, he went to a local hospital.

"I got in the Uber," the 43-year-old noted, "collapsed and woke up in a hospital bed attached to a machine with the doctor saying, ‘What on earth have you been doing, young man?'"

After returning from the hospital, Gordon said, he discovered Jamie had endured a similar experience.

"There he was with all this stuff attached to his chest," Gordon recalled, "he was saying, 'Gordon, about 20 minutes after you left, my left arm went numb, my left leg went numb, my right leg went numb. And I found myself in the back of an ambulance.'"

Though a source tells E! News Jamie never went into the hospital and "even played a game of golf the next day and won."

As for what caused the health setback?

While the Good Morning Britain host assumed the group had been experiencing caffeine poisoning from the slew of espresso martinis, Gordon said a doctor called asking if they had been in contact with processionary moth caterpillars while on the golf course.

"It turns out that there are caterpillars on golf courses in the south of Portugal that have been killing people's dogs and giving men in their 40s heart attacks," he shared. "It turns out we brushed up against processionary caterpillars and had been very lucky to come out of that one alive."

While the moths are harmless, when the insect is a caterpillar, it has "thousands of tiny hairs which contain an urticating, or irritating, protein called thaumetopoein," according to Great Britain's Forest Research. And the hairs can cause painful irritation and rashes on the skin, the eyes and throat when they come into contact with people and animals.

"So there's my story," he added. "The good news is it wasn't a caffeine overdose, it wasn't a hangover. It was a poisonous, toxic caterpillar."