I keep a a bag with wound stop powder, gloves and a tourniquet on my tractor. Duct tape would work for many emergency needs.
My uncle severed his hand in a bean header many years ago before cell phones and fortunalty JD had a first aid kit in the cab with a tourniquet in it. He tied off his wrist, grabbed his loose hand and drove the combine to the shop, got in his truck and drove to the hospital. Doctors said the tourniquet saved him. They actually put his hand back on his arm but it never worked right.