The nine celebrities who climbed Kilimanjaro - Africa's highest mountain - for Comic Relief have met Gordon Brown in Downing Street.
Girls Aloud singer Cheryl Cole, Take That's Gary Barlow and Boyzone's Ronan Keating were among those at Number 10.
Mr Brown told them they were "inspiring a generation of kids who would never have thought about these things" and added that they were "nine heroes".
He also announced the government would give £2m towards fighting malaria.
Ahead of the visit, speculation had mounted as to how the prime minister might mark the occasion after his spokesman was asked if he would wear a red nose.
He replied: "Wait and see." But, in the end, Mr Brown did not wear one.
Instead, a large red nose was placed on the door of Number 10.
The celebrities reached the summit of Kilimanjaro on Saturday.
The other six who made the top were Radio 1 DJ Chris Moyles, solo singer Alesha Dixon, Girls Aloud member Kimberley Walsh, TV presenters Ben Shephard and Fearne Cotton, and singer-actress Denise Van Outen
Several members of the group suffered from altitude sickness during the five-day, 19,300ft (5,900m) ascent.
They endured sleepless nights, as well as aches and pains due to the lack of oxygen.
Mr Brown said: "We are proud of everything that nine great heroes have done."
Mr Barlow, who came up with the idea of the climb, told the prime minister the celebrities had left their "comfort zone" in an attempt to do something extraordinary and hoped people give them money.
At the last Comic Relief event in 2007, Mr Brown's predecessor Tony Blair performed a comedy sketch opposite impersonator Catherine Tate.
In it, he used the catchphrase employed by one of her best-known characters, petulant schoolgirl Lauren, repeatedly asking: "Am I bovvered?"
It is not thought Mr Brown is planning to do anything similar for this year's Comic Relief show on BBC One on Friday.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.