Polystyrene foam, sometimes sold under the brand name Styrofoam, has long been popular among restaurateurs for lightweight, heat-retaining containers, but environmentalists complain it takes years to break down in trash.

WSJ: Foam cups, containers eyed amid NYC recycling push

United started the final, played in stifling heat, as if retaining their crown would be little more than a formality, creating a host of early chances against the nervous-looking Catalans, with Cristiano Ronaldo a constant threat.

BBC: Barcelona 2-0 Man Utd

Such devices can remove stale air from a home while retaining 85% of its heat.

ECONOMIST: Green homes

Bespectacled soldiers may have trouble training the sights of their guns, or retaining contact lenses in the heat and dust of battle.

CNN: Where Life Passes in a Blur