Incorrect Chuck. With the proper gear you can use a harness while climbing. But most hunting suppliers do not sell or advertise belay or fall arrest gear designed for use unless you are already sitting down.
It is called a ladder climbing devise. It attaches to the bottom rung of the ladder and is a wire that is stretched tight to the top rung. You are attached to the wire using camming system that slides freely going up, but stops you cold if you descend at faster than two feet per second. Take one step up and fall and it stops you in less than a quarter of an inch. If you are worried about falling while setting the stand up, then all you have to do is take a rope toss it over a sturdy branch
(Minimum of 8 inches thick for someone less than 300 pounds, there are other things to do if you don't have a branch that big, but we will cover that when someone asks), bring it down, tie a figure eight to your harness. Take a shorter length of rope tie a double half hitch around another tree at an angle (double half hitch is obviously tied near the ground on the trunk of the tree), and in the end of the rope tie another figure eight, pick up a self belay beaner from any one of a thousand climbing websites and use the figure eight in the tree on the ground, run your free end from the top rope through the belay beaner and pull it tight, tie another figure eight to the figure eight that is already tied to your harness then climb. It will allow you to climb and descend as normal, but if you fall it will stop you. Or you can set up with someone there to belay for you, That makes it so you only have to tie one knot.
Then if you are really big and out of shape, you could even go so far as to set up counter weights so you don't have to do all the work yourself, but that is another lesson for another time
Trust me they are worth it even when you aren't out of shape.
Edit: Sorry for the late info.
Using the above advice, you can set your anchor points on the tree while you are setting up for the first time, so you are 100% tied off the whole time. Go out to your stand before the buttcrack of dawn and hook to the ladder climbing device. Climb to the seat and tie off to your anchor point before unhooking from the ladder climbing device, then unhook from the ladder. No shaking like a leaf in the wind involved, no risk of falling, no risk of death, and ya can use any type of stand ya want without being scared.