Read it through once

"What has going or not going to the hospital to do with Chasuble's chance of winning the Cambridgeshire?" said the doctor. "This window is loose in its sash, a draught comes under the door, and if you close out the draughts the atmosphere of the room becomes stuffy. You're thinking of going abroad; a fortnight's nice rest is just what you want to set you up for your journey."