I also take a PLB when I go solo, just in case. However, far more important is a wilderness first aid course. It will not only teach you how to handle common (and some not-so-common) emergencies, but how to improvise bandages, splints, etc. out of whatever is handy so you don't have to take a 5-lb. first aid kit that you'll probably never use.

Other than a severe knee injury on an x-c skiing trip 20 years ago--I was with a group at a cabin, they had a ski-partol type toboggan and we were only about 45 minutes from the cars--I have not had any illness or injury other than the usual minor cuts, scrapes and blisters. My dog got sick on a trip last summer; when he barfed up his breakfast the second morning in a row, I turned around and went out. It turned out just to be his sensitive Labrador stomach, which responded to frequent very small feedings, but it could have been something serious.