Frankie Bridge suffered a panic attack for the first time in five years during the 'Sport Relief: The Heat is On' challenge.
Frankie Bridge
The 31-year-old singer trekked across the Namib desert in Namibia - alongside Nick Grimshaw, Louise Minchin, Rob Rinder, Krishnan Guru-Murthy, Samantha Womack, Karim Zeroual and Dr Zoe Williams - for the charity, and admitted it became "just too much", particularly when she thought the beetles were "laughing at [her]".
She said: "I had my first panic attack ... the last one I had was about five years ago. Great, it was on camera, typical.
"But also, part of me feels the whole charity is focusing on mental health. And what better way to explain it than someone seeing it.
"It's not what I would've planned."
When asked what might have brought it on, she said: "I think just the fear. You're having to hand yourself over and trust other people that you don't particularly know, and you're in an environment that you don't know.
"The middle of the desert is a scary place. It's so vast. It was so hot.
"At one point I was on my own for quite a long time.
"I got into my own head that nothing is alive there apart from beetles. And I got the point where I felt like the beetles were laughing at me as they were running past.
"They were so fast and I was so slow. It was just too much.
"I was fine the last three days. But on that first day, I thought, 'What am I doing?'
"I was gutted I had a panic attack, but you know."
Frankie shared a tent with Nick, who suffered from heat exhaustion on the trip, and joked they were like a "married couple".
Speaking on 'Lorraine', she added: "We were tent mates and ended up becoming like a married couple, it was quite funny.
"As much as I cried, I laughed even more on the whole trip.
"He's such a good person to be around. The team was amazing."
Louise recently admitted she didn't realise how tough the challenge would be.
The 'BBC Breakfast' presenter explained: "I knew it was going to be tough but it was out there!
"But also, utterly brilliant and you know me, I enjoy really difficult things but it was really far past difficult."
Tagged in Samantha Womack Nick Grimshaw Frankie Bridge