Singer Mike Posner said he was airlifted to hospital after being bitten by a rattlesnake.
The pop star, sporting a large beard, is currently walking across the United States and crossed from Kansas to Colorado on Wednesday, according to his Instagram page.
Hours later he shared a video from hospital, showing him lying in a gurney while being wheeled along by paramedics.
Posner, whose hits include Cooler Than Me and I Took A Pill In Ibiza, said he had been bitten by a baby rattlesnake and was taken to hospital by helicopter.
He wrote: “That venom is no joke! I got to the hospital and got the anti-venom in time. Shout outs to G and Mike from the chopper team and Bo and Cassie and Whitney (my nurses).
“I’ll be here a few days and will not be able to walk for several weeks but enjoying the AC and the nice bed, haven’t had those in a while Hahahaha!”
Detroit-born Posner, 31, added: “Can’t wait to get back on The Walk! KEEP GOING!!!!!!”
Rattlesnakes bites on people are rarely fatal, with less than 1 in 600 resulting in death, according to the US Forest Service, while 33% of bites do not contain venom.
Posner’s celebrity friends sent get well soon messages in the comments section.
Joe Jonas wrote: “Rest up bro. Glad you are OK.”
Millie Bobby Brown said: “What!!! Get well soon, sending best wishes to you.”
And Jessie J commented: “You are a real life super hero.”
Ponser embarked on a hike across the US in April, starting in Asbury Park, New Jersey.
He plans to walk 20 miles a day, reaching California in September.