I have severe asthma which has since been controlled with other medication. Fairly recently I gave mine to a lady who was experiencing an attack so can definitely vouch for this

I’m buying one now. Didn’t even occur to me but would be so helpful

In Australia, I only drink tea IF I’m feeling like it in winter which is it that often. Don’t drink coffee. And yet I’m still surprised it’s not something that’s in every house…

At some point it probably does. And can probably catch fire. Mine were fine once they cooled

Generally much less effectiveness to almost none as they get hotter

Source: was an idiot teenager