What Causes Reddish Patch Of Dry Skin On The Upper Leg With Swelling?

i am 47yrs old i do alot of walking bending and lifting in doing my job spend alot of time on knees and alot of time standing i notice on my left upper leg a large redness area with dry skin as well as a little sweeling after the 0degrees day in ny i had on muplite layers of clothing