Searing Smite

Duration: 1 minute, Concentration
The next time you hit a creature with a melee
weapon attack, it deals an extra 1d6 fire damage.
At the start of each of its turns the target makes
a Con save. On a failure, it takes 1d6 fire damage.
On a success, the spell ends. It can use it's action
to put out the fire.
At Higher Levels. Each extra spell slot increases
the damage by 1d6.