Before modern climate control, homeowners warmed homes by covering them with mink-fur siding and stuffing attics with down comforters. Efficiently adjust air temperature with today's Groupon: for $69, you get an air-conditioner or furnace precision tune-up from All Hi-Tech Heating & Air Conditioning (a $149 value), which serves the greater Seattle area.

All Hi-Tech Heating & Air Conditioning carefully calibrates home-ventilation systems to reduce the risk of electrical fires and amp up energy efficiency. For a furnace tune-up, vent whisperers will coax dirty burners, motors, and drainpipes into cleanliness before feeding the sentient hamsters that run the fan belts. After checking the heat exchanger for cracks, technicians will test electrical wiring and gas connections, oil the fan motor, and check carbon-monoxide levels in the house and vent pipe.

Homeowners can also call upon All Hi-Tech Heating & Air Conditioning to scrub down an air-conditioner unit's coils and filters and chase out penguin squatters attracted to its frosty temperatures. Before giving the final OK, technicians will cycle through each unit's operations, taking note of any leaks or tears in the system's space-time fabric.