I live in a 70’s house that has had double glazing installed but little else in the way of thermal improvements since then. Imagine the following situation. Yesterday was a mild winter’s day, temperatures around 10°C, and I was comfortably warm working at home. Today the weather’s changed, it’s been cold all night and now it’s hovering around zero and cloudy outside. Wearing the same clothes, and with the thermostat set at the same temperature, I feel chilly. After spending the morning cradling numerous cups of tea and still not warming up I finally turn the thermostat up a degree. Why, if the air temperature inside my house is the same on both days, do I feel colder today?