I used to volunteer for a first aid organisation and often we would be providing support for large events like county shows or sports events. The radios we use

I used to volunteer for a first aid organisation and often we would be providing support for large events like county shows or sports events. The radios we used were simple VHF radios on licensed frequencies. There was no encryption which meant anyone could listen in, so obviously we weren't allowed to discuss personal details over the radio. Depending on the actual event we may be covering a large area or uneven terrain, so the radios may not always work. For backhaul we'd either use our phone if we needed to call the emergency services or for larger events we'd have them onsite so they would forward the message on - for example to warn a hospital of an incoming patient (often it was in remote areas where the nearest hospital had limited A&E facilities) or to call an air ambulance.