It's the one on the thermostat:
Cornell University researchers conducted a study that involved tinkering with the thermostat of an insurance office. When temperatures were low (68 degrees, to be precise), employees committed 44% more errors and were less than half as productive as when temperatures were warm (a cozy 77 degrees).
Cold employees weren’t just uncomfortable, they were distracted. The drop in performance was costing employers 10% more per hour, per employee. Which makes sense. When our body’s temperature drops, we expend energy keeping ourselves warm, making less energy available for concentration, inspiration, and insight.
The Dish 