If a person is being dragged by a horse, the friction caused by the movement will make their jeans catch on fire.
Wearing full body padding and a denim shirt and jeans, Tory allowed himself to be pulled along the ground by a horse. While the movement and friction did increase the surface temperature of the jeans, it wasn’t enough to cause the jeans to combust. The Build Team then moved the experiment into the lab, where they simulated the friction caused by being dragged by a horse with a power sander. However, when they applied the jeans to the power sander, the jeans were torn apart before they could combust. The Build Team agreed that friction alone cannot make jeans catch on fire.