Here's a bit of info about harnesses that most don't know. Once you have fallen, you have less than 2 minutes to free yourself from the unfortunate situation. Should always carry a knife to cut the lanyard if you cannot get free. I build scaffold and have to wear a harness all of the time and this came up inone of our safety meetings. Apparently, after 2 minutes or so, the blood circulation is completely cut off from your lower extremeties and when you get freed after this happens, you are in great danger of heart failure due to the massive amount of blood rushing to your lower half. So be careful, wear your harness, and don't fall.