Sir Chris Hoy joined 300 of some of Scotland's most wealthy and influential people to spend a night under the stars to raise money for the homeless.
The Olympic cycling champion bedded down on Thursday night in Edinburgh's Charlotte Square for the CEO Sleep Out to raise funds for homeless charity Social Bite.
Social Bite plans to provide a low-cost, supervised and safe living environment for up to 20 homeless people with 10 purpose-built homes in Granton, Edinburgh, and needs to raise £500,000 for the project.
Posting his picture on Twitter, Hoy said: "Fingers crossed it stays dry."
Crowds appeared to be in high spirits with temperatures expected to be between 7C (44F) to 8C (46F) overnight - unseasonably mild for a Scottish winter. But participants made sure they wrapped up warm.
Speaking ahead of the event, Sir Chris Hoy said: "It's great to be on board and it's not as cold as I thought it was going to be - I was quite warm - a bit sweaty earlier on, but ask me again at 4am and see if I'm still smiling then."
Participants including Enterprise Scotland boss Diane Mulholland and Scottish Sun editor Alan Muir began arriving at 7pm for the sleep out.
Scotland's First Minister Nicola Sturgeon is due to serve the fundraisers breakfast at 7am on Friday.
Around £40,000 worth of camping equipment donated by Tresspass was given to participants upon entering the site which included a ground sheet, sleeping bag and a survival bag. After the event all equipment will be donated to homeless people in Scotland.
Social Bite co-founder Josh Littlejohn said: "We have actually managed to get 300 top people sleeping out for us tonight to raise money for a project to build a village for homeless people in Edinburgh to really break that cycle of homelessness.
"Sir Chris Hoy said he would come and do it very early doors so as soon as he said yes I knew we would hopefully get lots more and now we're up to 300 so it's really phenomenal.
"It will definitely be an eye opener for these people to sleep out for one night and do in Scotland what an average 600 people do every single night sleeping rough."