Records that serve the person, not only the file
What was done, by whom, and what was handed over.
A first aid record exists partly for the organisation and primarily so that whoever treats the person next knows what happened. Time of onset, what was observed, what was done and when, and any known history the person disclosed.
That information handed to paramedics changes care, and it is routinely not recorded because the responder is occupied. Assigning somebody to write down times while the responder works is a simple arrangement that makes it possible.
These records contain health information and are subject to privacy obligations that differ by jurisdiction. They should be stored securely, accessible to few, and retained for the applicable period rather than kept in a general incident folder.
The record also matters for any later question about whether the response was adequate, and a contemporaneous note written within the hour is worth considerably more than a reconstruction the following week.
Serious incidents carry notification obligations to a regulator in most work health and safety frameworks, with short deadlines and a requirement not to disturb the site. Those should be known in advance rather than looked up during the event.
It is worth adding that the record should note what was not done as well as what was, particularly where a responder decided against an intervention. That is clinically relevant information and it protects the responder if the decision is questioned.