Why is it not sensible to fix heaters high up in wall?

Fixing heaters high up on walls is not sensible because warm air rises, causing heat to accumulate near the ceiling rather than circulating throughout the room. This can lead to inefficient heating, as lower areas remain cold and uncomfortable. Additionally, high-mounted heaters can be harder to access for maintenance and may pose safety risks, especially in homes with children or pets. Proper placement at lower levels ensures better heat distribution and energy efficiency.