Dear Mr. XYZ,
You need to be highly commended for the way in which that you handled the particular emergency that occurred this (date and time).
These paramedics have informed us if you had not acted as quickly since you did, our customer’s/client’s attack has been serious. Thanks to your super fast reaction, now he is already outside of intensive care and on the road to recovery.
We are very proud of your association with this organization. Thank you,
Name of Authority..
Designation with Signature..