Ambulances, emergency defibrillators and walkie-talkies are all relatively new creations. (Getty Images)

It’s hard to imagine a world without emergency medical services — the first responders, surgeons and other professionals who can mean the difference between life and death for the people they help.

But not that long ago, the field didn’t exist.

Such things as ambulances, emergency defibrillators and walkie-talkies are all relatively new creations. Even CPR, one of the most well-known techniques, didn’t exist until 1960. So how did the idea of emergency medical services get its start? The National EMS Museum answers that question.

The virtual museum tells a story that stretches back 150 years. It includes exhibitions that show how emergency services evolved from stretchers and crude resuscitation techniques to today’s high-tech communication and treatment tools.

Exhibitions are split into three categories: a history of ambulances, a showcase of how emergency response equipment has changed over time, and the stories of some innovators who helped make EMS what it is today.

They include names you may never have heard, such as Asmund Laerdal, a Norwegian toy manufacturer who created ­Resuci-Anne, a mannequin used to teach CPR worldwide, and Nancy Caroline, a doctor who wrote Emergency Care in the Streets, the first textbook for paramedics.

The nonprofit museum is still expanding its collection, but it offers a glimpse of how far the occupation has come in the past century and a half.

Even now, it’s easy to overlook emergency medical responders until something goes very wrong. A glimpse at the museum — check it out at emsmuseum.org — is a reminder of the professionalism and grit of EMS practitioners — no emergency required.