Pop stars are not like you and me, despite what some say to demystify their celebrity.
When you and I fall sick, we go to the doctor, are prescribed medicine and maybe receive a medical certificate indicating we are unfit for work.
For a pop star, that MC would likely cost hundreds of thousands of dollars and massive disappointment among fans if he has a looming concert expected to attract an audience of thousands.
In local singer Tanya Chua's case last month, falling ill also meant the delay of her dream coming true when she had to cancel her debut concert on June 26 at the famed Hong Kong Coliseum.
Her flu had worsened and she developed acute laryngitis.
Looking subdued and sounding hoarse in a video posted on Facebook on June 24, Chua, 39, admitted that she was nervous about cancelling the show.
Comforted by the words of encouragement her fans posted, she added: "Having seen the comments, I feel more calm. I sincerely thank you for understanding. Apart from gratitude, I only have more thanks. Thank you for your patience and for your generosity."
In the words of Mr Ngiam Kwang Hwa, 53, managing director of Rock Records Singapore, her record label: "She sounded hoarser than a man."
To her fans on Facebook, she added: "I can't face you in this less than perfect condition and I hope you can understand this difficult decision."
Also last month, Stefanie Sun, another home-grown Mandopop star, soldiered on to perform a show in Chongqing, China, although she has not fully recovered from a bout of flu - only to have to go to a hospital after the June 21 concert.
Subsequently, her June 28 gig in Chengdu before a crowd of almost 40,000 went without a hitch and China portal ent.163.com noted that she was in tip-top condition. She will be performing at the National Stadium this Saturday as part of her Kepler world tour.
Seasoned performers Kit Chan and Dick Lee have "war stories" of their own.
During her last concert in Hong Kong in February 2012, Chan developed allergies and lost her voice a few days before the show.
Even up until the full-dress rehearsal with the Hong Kong City Pops Orchestra, she was experiencing "a lot of difficulties". And yet, she had two shows with an audience of 8,000 each night looming.
She decided to go ahead with the performances, relying on hot ginger tea and prayer to get her through.
Chan, 41, also learnt that technique, experience and skill make a difference.
"I had to really think about how I was going to produce each note, how to sustain it or how to avoid the voice-break, etc. It was no fun at all, but they saved my performance from being a total disaster. From then on, I had renewed esteem and respect for vocal techniques and learnt to not take them for granted."
She says of the occasions when she had to perform while sick: "Each one is like a scar on my heart."
As for Lee, he once came down with a bad flu during a stressful production of the musical Falsettos in Tokyo in 1994, in Japanese no less.
He had an injection which made him go "berserk" and trash the dressing room. The 57-year-old says: "Basically, I blacked out and when I came to, the dressing room was wiped out."
As he had no understudy, the performance had to be cancelled. But he was back treading the boards the next day.
Clearly, no one wants to fall sick and artists try their best to keep in the pink of health when touring.
For Chan, this means taking vitamin supplements, avoiding fried and spicy foods or phlegminducing foods and taking lots of soups, fruit and Chinese tonics. Moderate exercise, such as swimming, short runs and Pilates, builds up stamina and increases flexibility.
Vocalist Regine Han, 30, of local indie outfit lgf, says that keeping hydrated and having adequate rest is key. "I think people don't realise just how important water is for their body."
Staying healthy is a responsibility that extends to the accompanying musicians on tour with the stars as well.
Producer Kenn C, 47, who has toured with artists such as Sun, says: "We try to take extra care of ourselves so the show can run unhindered. For example, if food is suspicious-looking or not very clean, we won't eat it."
Should a member of the band, staff or crew fall ill though, there are no black-and-white rules in place for keeping away from the star of the show.
But producer and guitarist Eric Ng, 38, notes: "Everybody is a professional and no one is purposely trying to spread illness." He has toured with stars such as Wakin Chau and Sandy Lam.
Mr Ngiam adds: "They would feel very bad if they think that an artist has fallen sick because of them. Nobody wants to take that responsibility." So that would mean automatically taking measures such as keeping one's distance and wearing a face mask.
Ng points out that explicit "keep away" instructions are "not very nice". He says: "When an artist goes an stage, it's the collaboration of a whole team supporting him. Successful artists will want the crew to be as comfortable and happy as possible instead of acting like a big shot and imposing restrictions on them."
When precautionary measures fail, the mantra that the show must go on is one that many performers hold to heart. The decision to cancel a gig is absolutely the last resort. The financial cost can be upwards of $150,000 for a Singapore venue.
In the case of in-demand vaunted venues such as the Coliseum and Taipei Arena, rescheduling is no simple matter.
Mr Ngiam of Rock Records, which has a concert arm, One Production, notes: "It's very, very tough because most of the shows are booked one year ahead. The next available date could be one year later.
"Some people might ask, 'Why not reschedule?' But instead of keeping the money from the fans for one year, the right thing to do is to return it and then announce it when a new date has been found for fans to rebook."
It was announced that refunds for Chua's Suddenly Beautiful gig will be processed at the Coliseum till July 9. A new date for her concert there has not been announced.
Once a performance is cancelled, the cost of doing so will have to be added up. For a Singapore show, these include about $100,000 for the venue, typically $50,000 in advertising and the cost of the refund process, estimates Mr Ngiam. The total loss is "easily between $150,000 and $200,000".
American singer-songwriter Peter Cetera had cancelled the Asian leg of his tour in 2009, including the Singapore stop, over a dispute with the regional tour agent. Mr Ngiam ended up taking a five-figure sum hit even though he was refunded by the artist's management as it was not the local production company's fault.
While insurance for cancellations is available, concert organiser Unusual Entertainment notes that it is not mandatory. And Mr Ngiam adds that it is difficult to purchase such a policy in Singapore because it is not offered by most companies here.
There are other costs as well, as Chan points out: "There is also the pressure and burden you feel of letting so many people down. The whole production and creative team and crew, the producers who put up the money for the show and especially the fans who have bought tickets and have put time aside to come watch you, their anticipation and excitement and commitment..."
Veteran performers have learnt to take the vagaries of life on the road in their stride.
Chan says that she has come to understand the magic of a live performance. "It is the inherent dangers and threats, and the potential hazards that make each live performance unpredictable, and keep the performer and audience excited and anticipating. It is something that is built on hard work, skill, artistry, experience and realised through faith.
"If one is able to appreciate all this, then I think one can really learn to appreciate a good live performance."