Hello,
Given the symptoms, the person might be suffering from allergic rhinitis.
Usually there are lot of causes. Mostly airborne or dietary. She might be allergic to dust. Person feels better in air condition as AC filters out dust. But in normal conditions, person can come in contact with dust more.
So identify the allergic triggers and avoid them.
Next Steps
Treatment for allergic rhinitis should be started
Health Tips
Identify the allergic triggers and avoid them.