Recessed Lights

Most people who are serious about energy efficiency do not like recessed lights (also called pot lights, or high hat lights) because such fixtures can be the source of considerable air leakage. They difficult to seal.
In addition, light fixtures above the ceiling get hot and may be covered with insulation. This poses a fire hazard unless the fixture is designed to be covered with insulation, as some are. Recessed lights that are designed to be covered with insulation typically have a double shell with an air space between to help cool the fixture.
Where you see recessed light fixtures surrounded by insulation, look for a double shell on the fixture. You may be able to see a designation that included the letters IC, indicating appropriate for use in an insulated ceiling.
Some recessed light fixtures have plywood or drywall boxes built around them to keep the insulation away. Insulation was often applied over the box to maintain continuity of the attic insulation while separating the light fixture from the insulation. This arrangement is not common but is acceptable.

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