Here is a sample template you can use to write a letter of commendation for heroism.
To,
[Name]
Dear, [Name]
I am writing this letter to acknowledge the bravery of your heroic action on [Date]. I applaud your humanity and instinct to help someone in need.
This heroism is a testament to the quality of your being. I would like to thank you for your selfless and heroic act.
Sincerely,
[Your name]