Frost:

John came home one afternoon to find 221b the temperature of the South Pole.

"Sherlock!" he shouted. "Sherlock, where are you?"

Looking around, he saw his friend slumped in his chair, in front of a small glass bowl.

"What the heck are you thinking?"

Sherlock didn't move. John slapped him. Sherlock groaned and slowly sat up.

"Stay there." He went to go turn up the thermostat.

"Experiment," Sherlock said weakly. "I suppose the cold made me drowsy."

"I should say so. You could have died!"

Sherlock smiled weakly. "I suppose it's lucky I have my own live-in doctor, isn't it?"