Pop group S Club have joined forces with the British Heart Foundation (BHF) to raise awareness and research funds for heart conditions, following the death of band member Paul Cattermole.
The singer died in April aged 46 from an underlying heart condition, weeks after they announced a comeback tour.
In his memory, the returning group will now promote the BHF's Spotlight On campaign at their gigs.
They said if they can "help save one life" it will have been worth it.
The band are encouraging fans to raise awareness with the hand-heart gesture [as shown in the above picture] as well as by using the hashtag #showyourhearts.
Singer Bradley McIntosh told BBC Breakfast: "If we can help save one life doing this we'll have made a massive difference.
"So just by raising awareness and being here today, I think we'll do a good contribution to this cause."
Fellow singer Rachel Stevens noted how there had been "no signs" that Cattermole was unwell.
Jon Lee from the group described his death as a "massive loss", stressing how he had been "like a big brother" to him during the band days. "That's why this campaign is so important to try and raise awareness about underlying conditions," he said. "And Paul was 46, you know".
"You always associate heart [conditions] and things like that with older people, you don't think it's going to happen to people that are so young," added bandmate Jo O'Meara. "And since we lost Paul we're hearing so many stories of so many young people that are passing away of this.
"So for us to be able to jump on board and be a part of this absolutely incredible campaign is so important."
O'Meara went on to say how excited Cattermole had been about the upcoming reunion and how much of a shock it had been to them all when he died.
"I think it was just a complete and utter shock to be honest, because we just had no idea that Paul had a heart condition," she said.
"So obviously to find out that we'd lost him, it took us quite a long time to process the whole thing."
"It's been a really, really tough few months."
"How do you process that news?" asked Stevens. "But what was really special is that we had time afterwards to really take the time to just chat and share memories," she continued.
The BHF is urging people to shine a spotlight on heart and circulatory diseases and raise funds for research, noting how such conditions can often go undiagnosed for too long, until problems occur or it's too late.
Chief executive of the charity, Dr Charmaine Griffiths, said it "happens far too often" that "families are robbed of a loved one far too early".
"Every two hours, someone under 50 dies of heart and circulatory disease, which is why it's so important and [why] we're so grateful and honoured to be partnering with S Club to raise awareness of these conditions."
She continued: "Heart and circulatory diseases affect one in two of us in our lifetimes, and that happens at all ages. The more we can do to be aware of that and to look after our hearts, the better it will be."
Formed by Simon Fuller, S Club 7, as they were originally called, were one of the UK's biggest pop bands of the late 1990s and early 2000s, before disbanding in 2003.
They were known for catchy and inoffensive hits such as Reach, Don't Stop Movin', Bring It All Back and Never Had A Dream Come True.
In July, they released a tribute single to Cattermole entitled These Are The Days, which they'll perform on their previously announced 25th anniversary tour of UK and Ireland, which begins in Manchester next month.
Speaking to BBC Radio 5 Live, Stevens confirmed the tour would now be "a tribute to Paul" with the first show being "dedicated to the British Heart Foundation".
Hannah Spearritt has said she will now not be joining the tour so the group has since rebranded to the five-piece S Club - with Stevens, McIntosh, O'Meara, Lee and Tina Barrett.