Before a lot of people start saying I should think of the elderly vulnerable, it's a normal cough, so in reality this cough wouldn't be an issue if we didn't have Coronavirus going around.
But we do. This cough may be Corona, so you need to self-isolate.
Even if you are 100% certain that it is an ordinary virus, you need to isolate, because all viruses have the potential to be life-threatening to someone, and with Covid-19 hanging over us, the NHS can't deal with that as well.
I have a primary-aged child with mild asthma. There are children like mine in classrooms up and down the country. In the space of a year, kiddo once managed two ambulance callouts and an exciting weekend stay in hospital attached to an oxygen mask, due to picking up "normal" coughs. At the time, the NHS was there for my child and others in the same boat. Well, mostly there. The second time he had an attack we couldn't treat at home, it was after bedtime on a weekend evening, and there were no ambulances immediately available.
It was terrifying holding him through his struggles to breathe. I will never forget him asking me when the ambulance was going to get there, and having to tell him I didn't know.
I sat there holding him, wondering whether they would get to us in time with a nebuliser. They did get there, thankfully.
The NHS is shortly going to be overwhelmed. There is no capacity spare. Don't pass on your child's cough, because you don't know who's going to get it. Will it be sturdy Timmy, or will it be Jimmy, whose asthma is virally triggered?