WHAT makes scaling the UK's highest mountain more intimidating than its fearsome height and an unpredictable weather forecast?
Attempting to do it at the stroke of midnight ... and sandwiching the climb in the middle of a one-day, three peaks challenge.
That's the goal a team of fundraisers have set to raise money for the Katie And Friends appeal.
The appeal was launched last year to give five-year-old Katie Milliken, of Clarkston, East Renfrewshire, access to leading-edge proton therapy to treat an inoperable brain tumour.
Four fundraisers will scale more than 10,000 feet over three mountains to attempt to raise £5000 for the campaign.
Clarkston-based jeweller Kevan Scott organised the challenge – and enlisted the support of friends Grant Fraser and Stuart Niven, of Newton Mearns, and Gavin McCorquodale, of Giffnock.
They will set off tomorrow afternoon to climb 2866ft Goat Fell on Arran, all 4408ft of Ben Nevis, then 3192ft Ben Lomond within the space of 24 hours.
The schedule means they will begin their ascent of Scotland's highest Munro (mountains over 3000ft) at midnight.
"Just at the time you should really be heading to bed, if not be in it already, we will have a long walk ahead of us," said Kevan, 43.
"We do have torches, so that should help – it adds to the challenge.
"I was hoping for a clear, dry night and that the clouds would not be skirting across the top of Ben Nevis, but I fear that will not be the case. We will just have to do it in the drizzly rain."
Kevan has known Katie's mum, Louise, since their secondary school years and made the wedding rings for Louise and husband Ken.
"When I found out about Katie, it was something I automatically wanted to help out with," said Kevan.
Katie was diagnosed with a juvenile pilocytic astrocytoma tumour following an MRI scan at Yorkhill Hospital For Sick Children in January last year.
A nursery teacher had noticed a slight tremor in Katie's right hand and that she was occasionally unsteady on her feet.
The youngster had emergency surgery at the Southern General Hospital to relieve pressure on her brain.
Another MRI scan a few months later revealed the tumour had grown and Katie began an 18-month course of chemotherapy to shrink the tumour. She has three or four blood transfusions every six weeks because the chemotherapy drugs kill her bone marrow cells.
In spite of a series of major operations, and the sickness and hair loss caused by chemo, Katie's spirit has amazed Louise.
"She is a very bright, caring wee girl and keeps the nurses at Yorkhill on their toes – doctors, too!" said Louise.
"She loves playing with her wee sister and loves cuddly soft toys."
Katie, who attends Carolside Nursery, will start school in August.
She will continue to receive chemotherapy treatment for three weeks out of every six at the Schiehallion ward at Yorkhill until the New Year.
The family will find out from a scan three months after the chemotherapy ends whether the tumour has stopped growing.
More than £140,000 has so far been raised to send Katie to America for proton therapy, which is not available in the UK.
Proton therapy targets the shape of the tumour and avoids damaging healthy brain cells, which is important in growing children.
If Katie's chemotherapy proves a success, or if her proton treatment abroad is funded by the NHS, then funds from the appeal will be diverted to CLIC Sargent and the Samantha Dickson Brain Tumour Trust.
Louise added: "It is humbling to have received so much support from so many local people and shows what a great community we have here in Clarkston and more widely in Glasgow and beyond including Dumfries, Inverness and Aberdeen.
"Kevan has been looking for something he can do directly for Katie And Friends and has been a great supporter of the fundraising campaign – we are delighted this will be the last big event being organised.
"It is a big challenge and a brilliant effort."
The Three Peaks team plan to set out from Glasgow tomorrow morning.
If the seas are calm, a friend will transport them from Ardrossan to Arran and back.
But if the weather is poor, they will have to rely on the ferry – and time their ascent of Goat Fell to coincide with catching the ferry service back to the mainland.
Another friend will then drive them to Fort William, sleep in his car while the team climb Ben Nevis, then drive them to Loch Lomond's eastern shore, where they expect fellow appeal supporters to join them on the final stage of the challenge.
"The last one, Ben Lomond, is one that other people can come and get involved in who don't want to do all three," added Kevan.
"I think we have 10 or 20 people coming to help push us up the final hill – and carry us back down, all going well!"
This weekend's attempt is the latest in a long line of fundraising initiatives for Katie And Friends.
A team of 55 women took part in the Glasgow's Women's 10K last month for the appeal.
In February, some 500 children took part in the Katie Milliken Football Festival at Ravenscraig Sports Centre, Motherwell.
Red rubber wristbands bearing the appeal name are also being sold for a suggested £2 donation.
l To support Kevan, call 0141 638 6804 or see the website: www.katieandfriends.org.uk
By MAUREEN ELLIS