Stay away from the chimney. A grammarian will get my drift...............

I can tell you my solution, but you won't like it. Nobody would.
After I moved to the US, I began getting such horrendous cases of flu every winter, I thought I would die..couldn't breath, chest roaring and crackling, etc.

Then, in my early 20s, I nearly died, so took measures to save my own life; I began eliminating stuff from my diet; first red meat, then white flour, then white sugar, then processed food, etc. Each time I dropped something from my diet, I'd hack up phlegm for days, like what happens when a smoker quits, then I'd have a surge of energy afterward.

After I got through going cold turkey on all those main items, my stamina suddenly doubled when jogging, I never had the flu again, all infections stopped, and when I raised my kids that way, they didn't even get the sniffles.
I paid no attention even if they played in the snow in their shirtsleeves, since they never had the slightest problem.

Pic is of my 8 yr old daughter on my son's horse, Black Jack, pulling my 11 yr old son on toy skis, our farm near Morehead, KY.

Flu virus can be passed on even through breathing alone (so it doesn't matter that he was breathing through his mouth). If your classmate was only sick today, and your nose is "itching" today, it means that the incubation period has already passed, and you picked up a bug a couple of days prior (that, if you really are coming down with a cold or flu). Wash your hands often, take care of yourself, and get an annual flu shot. Some years it's more effective than others, but still better protection than none

Wash hands often. DO NOT touch your face at all when near anyone. You could wear a face mask too ...

I never get flu vaccine - or the flu. My mantra is : "I am a healthy, resistant organism !" It's worked so far - along with healthy habits.

Flu shot time. I got mine in October.

If all you are feeling is nose and throat itching, you do not have the flu.

Don't touch any women. You will get girl germs

Don't have an answer for you... 'sorry to tell you. If worried maybe you should had gone to the mask.