Final answer:
To treat an injured leg, it is recommended to elevate the leg and apply a cold compress. Rest, compression, and elevation are necessary to reduce swelling and promote healing.
Step-by-step explanation:
The best course of action for an injured leg would be to elevate the leg and apply a cold compress. This helps to reduce swelling and inflammation by constricting the blood vessels and numbing the area. It's important to rest the leg and avoid putting pressure on it, while also applying compression using a stretchy bandage and keeping the leg elevated above heart level to prevent blood pooling.