Oof OP.
Personally, I prefer open windows but your attitude absolutely stinks.
Firstly, given that you're apparently all masked up on the bus and schools are absolute germ pits at the best of times, the chances are that you're getting ill from where you work, and not from the closed windows on the bus.
Secondly, you do know there are other jobs that are just as valuable as teachers, right? And people doing those jobs may have serious health conditions which are exacerbated by the cold - even putting them in hospital, just like you.
@catelynjane listed a whole heap of serious medical conditions such as Multiple Sclerosis and arthritis which you dismissed as "not genuine". I am honestly speechless about how callous you have been.
COPD is another one to add to the list - the cold is a known trigger and yes, could put someone in hospital. Funnily enough, there are also immunocompromised individuals whose condition is made worse by the cold too.
Have a google and you'll find a very long list of medical conditions that are made worse by the cold, leaving people with extended periods of extreme pain, immobility, or hospital stays.
I have complete sympathy with wanting the windows open. I struggle with closed windows for a variety of reasons. But I'm not so selfish that I think my job, my wishes, and my health automatically trumps that of everyone around me.
I also think it's deeply ironic that you're complaining that no one cares about your health while you are displaying a shocking lack of care about the health of others, which may be equally as bad or even - gasp - worse than yours.