If you buy a house directly from a seller, without brokers, have an attorney keep your deposit in and escrow account. Too often, money held by the seller is spent prematurely. If the sale doesn't go though it's important that you can recover your funds.
If you have a room air conditioner, remove it for the winter or seal it up and insulate it. Water heater insulation jackets can work well for covering and insulating the air conditioner.