The problem is, water boils at 212 degrees. Except in special circumstances (mostly having to do with pressure), you can't really increase the temperature, you just make a stronger boil.
At higher altitudes, the boiling point is actually a tad lower.
It really was reading 215. Oh well, the brew day went off splendidly. I did a cross between Revvy's Belgian Blonde and Bluelinebrewer's Succulent Strawberry Blonde. The OG wort tasted mighty fine.