Royal Blood were "hospitalised twice" after the release of their debut album for exhaustion.
The rock duo - comprised of Mike Kerr and Ben Thatcher - have revealed they were forced to take a break after an extensive amount of touring and promotion of their critically-acclaimed 2014 self-titled record because of how intense it got.
Plus the 'Figure It Out' hitmakers' sound engineer even lost his testicle on the road, though the pair didn't say how.
Mike said: "We didn't get any sleep.
"We all ended up ill and we all got hospitalised twice. Our sound guy lost a testicle ...
Ben said: "He's alive and well. We won't go to into it."
Mike added: "What I will say is that he had it surgically removed and that night mixed the show. Drugged out. And I don't think it ever sounded so good."
And, although they were running out of energy, Mike says they never felt depressed and even if they had felt like giving up on the band, they'd have left knowing they'd given it their all.
He explained: "The work and the schedule was insane, but there really wasn't a low moment.
"We thought, 'This doesn't happen to any band ever, so let's just enjoy it.' If it ends tomorrow, at least we can look back on it and be like, 'Well, we took everything we could have possibly squeezed out of this.'"
The end of the tour in October 2015 felt like the end of a chapter for Mike, as he recalled destroying his bass guitar by bashing it on a door as a symbol of the record cycle and supporting shows being done and dusted.
Mike told the latest issue of NME magazine: "Afterwards, I remember just slamming my bass into the door and it splitting into 10 pieces. It felt like the end of that album. We were ready to close that chapter. I genuinely didn't smash my bass in a 'this will be cool' way; it was more like, 'I need to destroy this machine and start again.'"
Now they are gearing up for the release of their sophomore effort, 'How Did We Get So Dark?', which has been inspired by R&B more than rock music as the pair admit they are more into Drake, Usher and Kelly Rowland than their peers.
Mike said: "I don't really like a lot of rock music.
I mean, obviously I love a lot of it, but the tour bus is pretty spicy isn't it? It's pretty R&B-heavy. There's a lot of things where you'd be like, 'What the f***? You like that?'"
Ben added "Got a bit of Usher going on.
"The parties on the bus get wild. We're all dancing to 'Work' by Kelly Rowland by the end of the night. I love Drake and all that lot. In their shows and their production, you can really get something out of it and put it into your own interpretation and music."