Hello there..... Use your air conditioner. Air conditioning reduces the amount of airborne pollen from trees, grasses and weeds that finds its way indoors. Air conditioning also lowers indoor humidity and can reduce your exposure to dust mites..... Reduce pet dander. If you're allergic to dander, avoid pets with fur or feathers. .... Cover your nose and mouth if it's cold out.If your asthma is worsened by cold or dry air, wearing a face mask can help.....