Recent accidents on trails in the mountains near Salt Lake City bring safety to mind.  When you are out hiking, make sure that you stay within your limits.  If you are going to leave the trail, stay away from dangerous areas like cliffs and rivers.  Also if you are struggling with your health, be aware and don't overexert yourself.  Hike within your own limitations and choose trails that you can do.  If you want to do something strenuous, start with smaller hikes first and build up to your goal.