Event stewarding companies will undertake a risk assessment to identify any significant risks, hazards that can be eliminated, those that cannot, and the reasonable measures needed to reduce or control them. 

They will also have an incident and evacuation procedure and be able and ready to manage, with tact and discretion, any situation that could conceivably occur whether that be a medical incident, or unauthorised access.

Ask about the company’s level of professional indemnity insurance, as well as their emergency procedures. Note that individual event stewards are not required to hold an SIA license, but they should be fully trained and competent.