Hot Lava!

There's some strange sorcery occurring underneath our bathroom floor.  Strangely, the tiles are warm.  Very warm.  Like heated.  Sure, it's nice on our bare feet in the middle of winter, but ignoring the reason is bothering me.  With lack of any evidence, I'll go ahead and assume there's hot lava under the floor.  To be safe I'll start moving about the house on furniture and countertops.