Does a soldier receive any special reward for sacrificing his life to ensure the well being of his comrades?

Purple Heart for sure. There are a few stories out there about recent such soldierly sacrifices. A Navy Seal was awarded the Medal of Honor for this act, in conjunction with other acts during and intense fire fight. Also, a gunner in Iraq got the Purple Heart, and Bronze Star for falling on a grenade that was tossed into his turret. So, it's the circumstances that lead up to the act, and the command that the person belongs to. It's your book, but at a minimum, Purple Heart and Bronze Star