2 months ago I got badly sunburnt on my legs. Now they are fine but if I stand up for 30+ minutes then my previously sunburnt areas on my legs will go purple and blotchy. Based on my background studying A-Level Biology and having a passion for science, I would guess that I've damaged the blood vessels under my skin and so they cannot transport the deoxygenated blood back up my legs properly whilst I'm standing up. Could this be true? If so should I be worried, will the issue resolve it's self in time?