Ross McCulloch, from Kilmacolm, and Craig Usher, from Port Glasgow, will brave freezing and wintry conditions to walk 96 miles along the West Highland Way this December.
They want to complete the challenge in just seven days and instead of stopping off in B&Bs along they way to rest and recuperate, the intrepid pair will camp out in the snow in sub-zero temperatures which have been know to plummet below -20 C.
Everything the experienced pair of walkers will need for the trek will be loaded onto Arctic sledges and dragged along behind them.
The two friends, who are both 22, will begin walking on 18 December and hope to finish on Christmas Eve.
All money raised from the walk will go towards Glencoe Mountain Rescue Team, whose good work the keen hill walkers have seen first hand.
Ross said: "Craig and I regularly go walking all over Scotland.
"Luckily we have never been in any trouble but we have seen the mountain rescue team at work and they do an exceptional job - especially in winter."
The duo insist they are fully prepared and not underestimating the scale of the challenge, which they believe has never been attempted before.
Ross said: "Hundreds of people walk the West Highland Way every year but only occasionally in winter. When it is attempted winter participants will always travel light and stop every night to seek accommodation in one of the many B&Bs or hotels en route and also stop regularly for food and rest.
"We intend to complete the challenge carrying everything we will need for our seven days of travel - food, clothing, safety equipment and our two-man tent - on sledges behind us because a lot of snow is to be expected."
Ross and Craig have set themselves a fundraising target of £1,000 and they are appealing to local people to help them meet it. So far they have raised £200.
To sponsor the friends online visit www.justgiving.com/winterchallenge or text WHWC69 followed by the donation amount to 70070. For more information on the walk contact Ross and Craig by emailing email@example.com