Final answer:
Athletic trainers should check the status of emergency communication devices such as telephones at least daily to ensure they have access to EMS in case of an emergency.
Step-by-step explanation:
An athletic trainer should ensure that emergency communication devices such as telephones are in working order to maintain access to emergency medical services (EMS). While the frequency of checks can vary by organization, there is a general consensus that checks should be regular and systematic. It's recommended that such checks be performed at least daily, to ensure that in the case of an emergency, communication lines are functioning properly and help can be quickly summoned. This regular check helps in timely and efficient coordination during critical situations.