Emma Willis, Oti Mabuse and Rylan Clark's mountain trek for Red Nose Day has been postponed due to poor weather conditions in the Highlands.
The trio have spent the last two days climbing and camping in freezing conditions and had planned to reach the summit of the Cairngorms today - but they have been told it's too dangerous to continue their hike.
Winds are reaching 70mph winds with gusts up to 100mph expected at the summit and specialist teams are frantically trying to find a safe route for them to re-attempt their mission.
It's hoped they will be able to complete their mission in 24 hours' time - if it is deemed safe to resume.
The celebrities set off from the village of Braemar, near Aberdeen, on Wednesday morning and made their way through the foothills of the Southern Cairngorms before setting up camp in windy conditions.
Over the last two days, they have battled blustery winds, ice, rain and freezing temperatures in their bid to raise funds for Comic Relief's Red Nose Day.
Strictly Come Dancing: It Takes Two host Clark, 34, admitted that if he was told two days ago they could not get to the summit he would be "delighted", but now they have gotten so close he was "absolutely gutted".
He added: "I know it's the right decision but we're gutted. Even if there's the smallest chance of us being able to carry on tomorrow then I'm staying. I didn't start this challenge to only make it halfway."
The Circle presenter Willis, 46, was also frustrated by the situation and said she was determined to see the challenge through to the end if it was at all possible.
She said: "I feel like the rug's been pulled from under us. If there's even the smallest chance of us trying again tomorrow then I'm staying. I'm not going home today. No way.
"I feel like I've only done 50% of the challenge and I always give 100% to everything I do. But it's out of my control.
"I can't get lost in my own disappointment though. I need to turn my annoyance into determination."
Dancing On Ice judge Mabuse, 32, added: "It's not the result we were hoping for and I'm not good with change. It doesn't matter what we want now. It's up to the mountain whether this challenge carries on tomorrow or not."
Expedition lead Graeme Douglas, who has been with the trio throughout their journey, emphasised that safety with all Comic Relief challenges was their "number one priority".
He added: "We have been closely monitoring the weather over the past 24 hours and due to 70mph winds and gusts up to 100mph expected on the summit of Cairngorm today, we have reluctantly made the decision to pause the climb until tomorrow.
"We have revised the proposed route and weather permitting, we will press on to the summit on Saturday."
The trio's adventure has been filmed for a documentary, Frozen: Emma, Oti and Rylan's Red Nose Day Challenge, which will air on BBC One and iPlayer in the run-up to Red Nose Day.
Money raised for Comic Relief's Red Nose Day will help the cost-of-living crisis and tackle issues such as homelessness, mental health problems, and food poverty in the UK and across the world.
A portion of the money raised will also go towards the emergency response to the earthquake in Turkey and Syria.
Red Nose Day returns to BBC One on March 17 with hosts AJ Odudu, David Tennant, Joel Dommett, Paddy McGuinness and Zoe Ball.
Get the latest celebrity gossip and telly news sent straight to your inbox. Sign up to our daily Showbiz newsletter here .
