Australian band 5 Seconds Of Summer were forced to cut their Texas show short after drummer Ashton Irwin suffered loss of vision and "symptoms of stroke" while on stage.
The 27-year-old was performing with his 5SOS bandmates - Luke Hemmings, Michael Clifford and Calum Hood - in Houston as part of their current US tour.
In a post on Twitter, Irwin explained why the band suddenly left the stage during their show on Sunday, writing: "I suffered from an intense migraine brought on by exhaustion and overheating onstage which made me loose (sic) my vision and gave me symptoms of stroke in the left side of my body. So the decision was to end the show there and then."
In a number of follow-up tweets, Irwin continued: "It's always amazing to play a massive energetic show in every environment thrown at us. Unfortunately this time my body gave out due to heat exhaustion. I was in tears in the ambulance, because I feel I've let many people down. I'm looking after myself and getting rest now.
"I feel so loved and looked after by my brothers and team and all of you. this is the price a dehydrated drummer pays when he takes on Texas heat. All will be made right, ticketing wise, and rescheduling wise. I love you. Thanks for the love. I'll be back onstage ASAP! X"
5SOS have released four albums since 2014, and are set to release a fifth, 5SOS5, in September.
The band also took to their official Instagram account to provide an update on Irwin's health, and announce they would be postponing a forthcoming show.
In an Instagram story they wrote: "Following medical advice, we will be postponing our show in Arkansas tomorrow night. The new date will be July 26th so Rogers, AR, will officially be our last show of the North American TMH tour!
"We are so sorry to cause inconvenience to your plans, but we promise for those of you who can still make it, we will put on the show of your lives.
"In the meantime, please join us in giving Ash the privacy to rest up and get back to full fitness."
Australian Associated Press