What Causes Redness On The Lower Leg?

I have diabetes Type II. I have red skin in the area of my lower legs approximately between my ankle up to mid calf bilaterally. I have been told this is a circulatory problem that many diabetics have. I have not had any problem with it until last night when I started having chills all night & the area on my left leg that is red started to burn & got redder than it has been in the past. I also had to urinate about every hour but this might not be related. This morning I am fine except the Red area is still bright red & burning.