The Rolling Stones reportedly keep a special heart machine backstage in case one of them collapses.
Organisers of their current tour have allegedly brought in a defibrillator in case one of the ageing rockers - who are all in their late 50s and early 60s - has a heart attack while performing.
The machine shocks the heart back into a normal rhythm, so a doctor would be able to revive the stars on the spot instead of waiting for emergency services.
A source is quoted in America's Globe magazine as saying: "With all four band members now veterans, their managers are not taking any chances."
However a spokesman told Britain's The Sun newspaper: "I've never seen a defibrillator backstage."
Last month the legendary band revealed they want to play a special concert in Iraq for British and American soldiers.
Frontman Mick Jagger says the rockers would be prepared to perform in the war ravaged country to raise the troops' morale but only if they are asked by military chiefs or the US or UK government.
He said: "The boys are doing a very professional and a very tough job over there and they aren't getting a lot of fun. If we were asked to go it would be a very, very serious consideration."
