A PMHNP working in an outpatient psychiatric clinic is conducting a follow-up appointment with a 52-year-old male patient being treated for generalized anxiety disorder. During the visit, the patient reports new-onset chest tightness, diaphoresis, and left arm numbness that began 20 minutes ago. He states he thought it was a panic attack, but it feels different from his usual anxiety episodes. The clinic does not have emergency medical equipment beyond a basic first aid kit. What is the most appropriate action by the PMHNP?