It’s common (relatively) - viral illnesses increase risk of myocarditis and especially if exercising. Hence the risk of myocarditis with covid infections/vaccines that got all worked up, but it’s the same for many other viruses.
General advice of any symptoms below neck (so not just a runny nose or mild sore throat) should lead to rest.
I’m the same but it is getting easier as the weather warms up and the coughing has pretty much stopped
Did a hard hour on the bike at lunchtime and, whilst still feeling the wheeze / constricted lungs it’s getting back to what I consider more normal, given I have asthma
It was odd that, whilst, suffering this “my lungs feel less efficient” issue I felt fitter in the water than usual !
The problem is so much of this is subjective. I used to check my temperature and if it was OK then I’d train.
A friend of a friend died while waiting for a heart & lung transplant because she didn’t know when to stop exercising when she was ill. Some kind of virus and I think led to what Chris says with the heart problems.
I raced her as well, pretty capable and experienced and I’m fairly sure she’d done Ironman’s etc.
A very extreme case but generally these days I stop for a few days unless I’m convinced it’s just something like my sinuses.
This happened to someone Mrs FB worked with many years ago. He’d been off ill with a bout of flu, came back and at the weekend played a game of football. In his early 30s, very fit, came home from the game and collapsed later in the day and died in hospital shortly after. Autopsy gave cause of death as viral myocarditis
One of my best mates nearly copped it with this last summer. Mid 40s, super fit and healthy. Felt super crappy the night before, passed out etc. Rang the ambulance but then in the long waiting time felt better so they cancelled it.
Him and his wife were lacing up to go for an easy run the next morning when an ambulance turned up at the door. The systems had gone down and they didn’t get the cancellation. Said they’d test him anyway as they were there. 5 mins later he’s told to get bags packed and they’re blue lighting up to Exeter. Docs said had he gone out and done his run that day, it could well have been it. Seriously scary shit.
Edit - realised I hadn’t chatted to him for a while so dropped him a text. He’s currently in hospital for his final mri/ecg to hopefully be given the all clear. Weird coincidence.
Oh great, new fear unlocked. Get a cold, die of a cardiac arrest.
Could say its rare, but the last 3 posts are people knowing someone who did or almost did.
Next cold I get I am going to bed and not moving a muscle until I am recovered.
You never want to work with paramedics. You’d never go to bed in the first place 
I’m fairly sure that the only I mentioned was as much because she did it quite regularly and was probably a bit more than a cold.
But I still use caution these days, apart from anything else I just can’t see how any training would improve you.
The problem is if I missed training every time I thought I was unwell I’d miss at least half my sessions !
This “listen to your body” stuff is all very well but it’s essentially subjective.
I feel I have a tight chest at the moment, and I have felt like this for a good few days now, but I actually felt fairly strong in the water on Monday night.
I remembered I bought a blood oxygen meter during Covid and that is one of the objective measurements one can make, temperature and resting pulse being the others I can think of. I’d have thought it a good idea to check up on those parameters if not feeling 100%.
HRV is another marker as well