I've always believed that businesses, no matter the size, have a responsibility to protect those they interact with and the general public, to the best of their ability. For my part, that entails putting together and carrying a first class first aid kit, complete with AED, tourniquets, bandages, and various other gear designed to treat field emergencies.
If you ever want to put one together yourself, remember these tips: Subdivide and clearly label everything by type of emergency. Make sure everything is water resistant, since you may be using it in the rain. Make sure you have light so you can operate at night. Don't forget to include water, blanket, and a towel. It's the little things that make all the difference in an emergency.
Don't forget to get proper training as well, from an organization such as the Red Cross or American Heart Association. Also, i can highly recommend the book "Medicine for the Outdoors" by Paul Auerbach. It's a very in-depth wilderness medical guide written for laypersons.