Many residential buildings built in the 80s and 90s have an abundance of recessed can lights. As you can see in these photos they are often directly connecting the attic to the living space. The infrared (temperature sensing) image shows the air migratingn through and around this type of fixture during a blower door test. This is an unwanted energy loss in many of these buildings. This can be resolved by installing an airtight box over the top of this fixture and then sealing it to the attic floor or being replaced with an energy efficient LED retrofit recessed light.
This can be resolved! Installing an airtight box over the top of these fixtures and sealing it to the attic floor is one option. (WARNING: Be sure to used an approved cover for this type of high temperature producing fixture.) These fixtures could also be replaced with an LED retrofit kit and then caulked at the trim.