Nursing and EMS are related to medicine, the onus is on you to prove otherwise if you're referring to the typical care that is provided by both fields when it comes to hospitalization. For the sake of humor, nurses in med/surg specialties are often responsible for physical assessment of patients following post-surgery whether it may be a crani, stent/pacemaker, PTX, etc. Failure to assess and also manage bulbs, lines, and drains can have significant complications when nurses aren't providing symptom management within the order protocols outlined by the physician. This applies even more so to EMS that involve professionals responsible for medical stabilization of patients who often need surgery to address their current circumstances with paramedics being authorized to administer medications like nitroglycerine, naloxone, bolus fluids, and D5W/NS/insulin/glucagon in emergent medical situations.
When you're assigned to a patient to give them medical treatment and you have the corresponding license, then you are qualified to treat that patient. There are situations like the Good Samaritan principle which promote good stewardship outside of the hospital if you notice someone in a critical condition who needs help that you can provide within scope of practice. I think that writing off EMS as a non-medical field is ridiculous when a large number of patients are able to make it to the hospital for further stabilization thanks to medical stabilization by EMS.