A newly-developed heat-ray gun that burns the skin but doesn't cause permanent injury is now with US troops in Afghanistan.
The Active Denial System (ADS) is a non-lethal weapon designed to disperse violent crowds and repel enemies.
It uses a focused invisible beam that causes an "intolerable heating sensation", but only penetrates the skin to the equivalent of three sheets of paper.
The discomfort causes whoever it's pointed at to immediately start moving away. They often scream but the US military says the chance of injury from the system is 0.1%.
It's already been tested more than 11,000 times on around 700 volunteers. Even reporters have faced the heat-ray.