It is great that you are concerned for your brother's health. You are correct that he should first make sure that his injury
is just a mild sprain without underlying bone injury. His primary care physician
can help evaluate his injury.
Ice is usually better for an acute sprain to help with the associated swelling. A way to remember the appropriate steps to treat swellings and sprain is RICE (Rest, Ice, Compression, Elevation). Rest is important because without it you can cause more strain to the area, leading to more inflammation and possibly further injury. Ice, as you might already know, is wonderful for swellings and sprains because it not only helps relieve pain, but also decreases the inflammation. To use ice appropriately, you should place it on the affected area for about 20 minutes and then let the area relax. You can wrap the ice in a paper towel or thin towel so that the ice is not directly on the skin. However, you do not want to overuse ice because it can lead to decreased blood flow to the area. Compression with an ACE bandage can help decrease swelling from the inflammatory process. Again, you do not want to overuse compression or wrap the area too tightly because you can decrease blood flow. Lastly, elevation of the affected leg above the level of your heart will help decrease the swelling. This works by increasing blood flow back to the heart instead of allowing it to pool in the leg.
Even though these treatments can help with symptoms, your brother should absolutely follow up with his primary care physician to ensure there are no other worrisome symptoms.