Another tenant is intentionally endangering me. What do I do? Is it the tenant's problem or the landlord's for not evicting her?

I am one of 5 people living in a house. 4 of us are tenants & the 5th is the landlord. We're all college students (including the landlord): him/his parents own the house. I'm extremely allergic to incense, scented candles, & perfumes, but one of the tenants hates me and is intentionally burning incense/candles in her room, the hall, in my room when I don't lock my door, and spraying my cat with perfume. I notified her of the problem, the landlord has told her multiple times that she can't burn them any more, and the owners have told her. She said she'd stop but won't. Last week I stopped breathing and had to go to the ER. When the landlord told her, she said "so what" & burned more incense. What do I do? This really can kill me! Do I file a restraining order? Hold the landlord liable?