Some people put aluminum foil behind heaters, and the effect proves that this is true

With less heat lost to the walls, your heating system may need to run less often, potentially saving energy and reducing costs.
How to Do It Properly:
Use heavy-duty aluminum foil or, even better, specialized radiator reflective panels available in stores.
Attach the foil with the shiny side facing the room or radiator.
Ensure it’s securely taped or mounted to the wall behind the radiator, leaving enough space for air to circulate.
Effectiveness:
The effect is most noticeable in older homes with poorly insulated walls.
Modern homes with good insulation may see less of a difference but can still benefit.
Precautions:
Make sure the foil doesn’t block any vents or airflow around the radiator.
Avoid using this method on electric or space heaters, as it may not be safe or effective.
This simple trick is a great way to boost heating efficiency, especially in colder climates or during the winter months!