Related Clues:

• Falling behind
• Trailing behind
• Wrapping used to prevent loss of heat
• Insulating material
• Getting behind with job in the attic?
• Not up to date with thermal insulation?
• Staying behind, so wrapping up well
• It's used to wrap around boilers, say, to prevent heat-loss
• Trailing insulation
• Insulation — failing to keep up
• Jacket to wrap around a boiler to prevent heat-loss