The sister of a coronavirus patient from Renfrewshire believes her brother would have died if he had been living alone when he caught the virus.

Paisley man Calum Wishart, 25, is in The Royal Infirmary of Edinburgh after falling ill over the weekend.

He had been fit and healthy before coming down with Covid-19 and said the tell-tale symptoms are fever, coughing fits, vomiting and diarrhoea.

Calum has cautioned people to stay inside and warned youngsters to take the threat seriously and not believe the virus will only affect the elderly or vulnerable.

He said: “Everyone needs to do their part and start taking this seriously.

“I don’t care how boring you think self-isolation is, I can guarantee it’s a million times better than this.”

Calum had been self-isolating in Edinburgh after he developed symptoms while visiting his parents before the lockdown.

He was admitted to the ERI in the early hours of Saturday morning after his health deteriorated.

Older sister Rachel, 27, believes he would have died in his Paisley flat had he not been admitted to hospital from his family home.

She said: “Calum plays sport, he’s healthy, he’s got a good diet. He’s the last person in our family I thought would get the virus.

“I can’t think about what would have happened if he had been in that flat alone. I honestly think he would have died. It took a really bad turn so suddenly.

“Calum is quite a joker. He’s normally quite flippant about things but I can tell that he’s scared.

“He just wants to put the message out that no-one is safe from this. There are still a lot of people not taking this seriously and not taking advice.

“This time last week, I was still taking my children on walks. Like everyone else, I was naive – I thought, if I got it, I would be fine but I’ve got three children who depend on me. What would happen if I was in hospital for weeks?”

In a post on social media, Calum urged people not to go outside, even for exercise.

He wrote: “The reason I’m posting this is that I’m still seeing people go out for non-essential reasons and people going to non-essential work.

“No business or reason for going out other than food or for medical reasons is more important than [avoiding] this experience.

“So all of this nonsense about going out for exercise has to be ignored. The government have no idea what they’re talking about and they’re gambling with people's lives.”

Calum agreed with his sister that paramedics saved his life.

He said: “I don’t think I would have survived without the oxygen that the hospital have been able to give me.”

Calum also described some of the symptoms he has been suffering with.

“The coughing is so aggressive that it gives me massive pain all over my chest and a lot of the times induces the vomiting and diarrhoea, sometimes all three at once," he said.

“Sleep is pretty much impossible as well, which is excruciating because that is literally the only escape from the horror of the symptoms.”

Rachel also praised NHS staff who have been caring for her brother.

She said: “They have been incredible. They could not have taken better care of him but they need to be supported and protected by the public.

“Calum can see what’s going on at the hospital and, if this keeps going, there aren’t going to be enough staff or enough ventilators.

“Young people think they’re invincible, they think that it’ll just be a cold or a 24-hour bug. People need to listen, they need to take this seriously.”