You can use hot wax on every part of the body but as Male Waxing said, it'll take longer.
Very few salons these days offer a choice of hot or strip for legs but if they do, they generally charge 60% to 100% more because of the cost of the wax and the time involved.
Take a large scoop of wax and run it from under the knee at the side of the leg to the ankle in one long strip, leave a gap (where the shin bone is) and apply another strip on the other side of the outer leg. Remove, remove and then apply your third one in the same way over the shin bone.
Good luck.