Ambulance

Ambulances in the early 1900's were very simple. Before World War I, ambulances, especially in rural regions, were largely horse drawn carriages. In 1909, the model 774 Automobile Ambulance was mass produced and it featured a proprietary 32 horsepower (24 kW), 4-cylinder internal combustion engine. The chassis rode on pneumatic tires, while the body featured electric lights, a suspended cot with two attendant seats, and a side-mounted gong (McCall, Walter MP. 2002. "The American Ambulance", Iconografix).
During World War I, the motorized ambulance was deployed to save the lives of soldiers on the battlefield, and made a significant impact on the healthcare industry back at home as well (https://www.inquirer.com/philly/blogs/public_health/World-War-I-debut-of-the-motorized-ambulance.html)