What Should Be Done To Remove Asbestos On The Forearm?

my son was working on brakes on a truck and abestis got on his forearm. He was told by co workers not put hot water on it. To wash arm with cold water. Another person told him to use tape. He did he said he got some off forearm,. But when he shirt on this morning he can still feel some still on skin. What should do to remove abestis off forearm>