We are wasting millions, contributing more to global warming than industry, letting pensioners get cold despite free central heating systems they can't afford to switch on, and letting kids get asthma in damp cold bedrooms and overheated classrooms.

BBC: The ?1,000-a-year heating bill is here.

Heating and cooling experts say central air-conditioning systems should be serviced annually to remove dirt, change filters and check the level of Freon, a refrigerant.

WSJ: Don't Wait to Service AC Units