This Wheelbarrow Pool Heater
This person really wanted a heated pool, so they placed a wheelbarrow in the water and lit some kindling on fire. What happened next was that the metal from the wheelbarrow got really hot and eventually warmed up the water in the pool. That was a pretty ballsy move considering that they set the wheelbarrow up in an inflatable pool. Luckily, it was far enough from the edge that it didn’t melt the plastic material or the whole pool would have deflated.