It sounds ridiculous but my kids are extreme prems and were incredibly unwell. Both have chronic lung disease although luckily they are not on oxygen anymore and I've told people who want to visit not to smoke for 24 hours because I don't want my children exposed to second hand smoke when they've had problems with their breathing already. Apparently some people have said they think I'm bonkers for this.
Is it too over the top? They were both vented, both struggled to lose the oxygen.