I know...but it beat banging your head against the wall out of frustration.
have you taken him to the doctor? might be wise, to be sure of what you are dealing with is always good.
My little guy got those too. There is some truth to the growing pains. The bones grow during the night. Many times, the bones can grow enough to stretch the muscles and cause pain. The heat is good and massage helps too. My little one is now 21 and over 6 ft. tall. It will pass.