Exhaust Smoke

You create a 30-foot cone of smoke from your position. The cone spreads around corners, and its area is heavily obscured. It lasts 1 hour or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it. Each character in its area must succeed on a Constitution saving throw or take 1d8 damage. A creature that enters or ends its turn in the area must also succeed on a Constitution saving throw or take 1d8 damage 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d8 for each slot level above 1st.