Status Quo's Rick Parfitt is being treated in hospital in Turkey following a suspected heart attack.
The 67-year-old guitarist was taken to hospital in the early hours of Wednesday morning following a gig at Expo 2016 in Antalya, Turkey.
In a statement, his management said: "Whilst his condition is serious, he has already demanded his customary cup of tea with two sugars and a sweetener."
The band's manager Simon Porter added: "No further comment will be made at this stage until the completion of the next round of tests and assessments to be made over the next few days.
"We would ask you to respect the family's privacy at this difficult time."
A self-confessed former drug addict, Rick has suffered a catalogue of health problems, including a quadruple heart bypass in 1997, a throat cancer scare in 2005 and a heart attack in 2011.
Status Quo were forced to cancel a series of gigs in 2014 after singer and guitarist Rick was told to rest by medics following surgery to correct a problem with his previous heart bypass.
He fell ill during the band's European tour and was flown home from Croatia to be treated at the Royal Brompton Hospital in London. He had a stent inserted after it was found a graft from his heart bypass had become furred.
Rick has pulled out of a performance at Rock On Windermere charity show on June 18 to raise funds for the Cumbria Flood Appeal.
However, the rest of the band will appear, with Freddie Edwards, the son of Quo bassist John "Rhino" Edwards, stepping in for him.
It is likely that Freddie will stay with the band until Rick has recovered, including for their upcoming show in Sweden in July.