Call emergency services immediately
Chew aspirin only if the person is not allergic and has no bleeding risk and emergency guidance allows it
Help the person sit or rest in a comfortable position
Loosen tight clothing
Keep the person calm and still
Give nitroglycerin only if it was prescribed for them
Begin CPR if the person becomes unresponsive and is not breathing normally
Use an AED if available and follow the prompts
Do not let the person drive themselves
Do not give food or drink
Do not delay getting emergency medical help