Benedict Cumberbatch took part in a charity swim for U.K. Red Nose Day on Friday, but this was no ordinary morning splash-about.

The Sherlock actor braved temperatures of 7.8C (46F) to swim in Hampstead Ponds wearing nothing but swimming trunks, a red nose, and a red nose headband.

Hampstead Ponds are a group of freshwater swimming ponds located on Hampstead Heath, a vast grassy public space in north London. Any Londoner can swim in the ponds for a small fee of £2, but understandably, they're much more popular in summer than at other times of the year... like March!

Cumberbatch was joined in his charity swim by Alexander Woollcombe of nonprofit organisation United for Global Mental Health. The pair were aiming to raise money for Comic Relief's mental health programs, cheered on from the safety of dry land by The Great British Baking Show host Noel Fielding.

Author Laura Mucha shared a picture of the trio on Twitter.

https://twitter.com/lauramucha/status/1106616321851248640

We'll be seeing a warmer-looking Cumberbatch in superhero sequel Avengers: Endgame, which opens in theaters on April 26. This will mark the actor's fourth appearance as Marvel's neurosurgeon-turned-superhero Doctor Stephen Strange.

He's also finished filming Ironbark, a Cold War drama in which he plays real-life British businessman Greville Wynne, who helped the CIA penetrate the Soviet nuclear program. This movie has no confirmed release date yet but it's expected later this year.

Do you think you could stand swimming in super-cold water like Benedict Cumberbatch?