Young people at Wolverhampton's Khalsa Academy joined hundreds of their peers across the country for the 12-hour televised fundraiser.
More than £40,000 has since been raised for good causes across the country, including cash for medics treating sick children in the region.
The five-day nationwide telethon marked Saka Sirhind, which recognises the sacrifices made by the young sons and mother of the tenth Sikh guru, Guru Gobind Singh.
Nick Singh Kandola, chief executive officer of Khalsa Academies Trust which manages the school, said: "This amazing event demonstrated the significance of the unique sacrifices made over 300 years ago whilst raising funds to support children’s wards in NHS hospitals and a homeless project across the country.
"One of the most important values that are taught at these schools is 'seva' which means to help those in need.
"We are immensely proud of all the students, parents and the wider, community and would like to thank them and the Sikh Channel who have made this amazing event possible."
More than 500 students and their parents came, representing a total of four schools, came together during the Christmas break to take part in the fundraiser.
Each school hosted the sleep-out for one night, with the UK-based Sikh Channel broadcasting the fundraising efforts.
Other pupils took part from Buckinghamshire's Khalsa Secondary Academy, Ilford's Atam Academy and Coventry's Seva school.
Students from Wolverhampton decided to support Birmingham Children's Hospital, with a slice of the cash set to support young patients treated there.
Principal of the Millfields Road school Anita Notta said: "Our highly talented students started the evening with a prayer to commemorate the sacrifices made by Guru Gobind Singh Ji.
"They choreographed and presented a spectacular martial arts demonstration at the interval and were applauded by the congregation for their hard work. The event concluded at 9am the following morning with more hymns."
Sikhs commemorate the family of Guru Gobind Singh during December, often singing hymns and ballads outside in the cold.
It marks the deaths of the guru's young sons, who were bricked alive after being trapped in a cold tower with their grandmother.
Cash can be donated to the online fundraiser until January 25.