This ^^^^ apart from the "if you burn easily" bit. Do it even if you DON'T burn easily. I had a VERY lucky escape last year while undergoing allergy "patch tests" on my back, the dermatologist spotted a dodgy looking mole. Long story short, it was removed within a week, and found to be a cancerous melanoma. A second operation was done to remove the surrounding skin, and luckily that was all clear. Had it not been, it could have been very bad news.
As a result, I will be the guy on the bike NOT wearing shorts unless unbearably hot - which is hardly likely in the west of Scotland! And the exposed parts will be treated with factor 50 prior to exposure. This was the advice of my dermatologist, who told me that anything less than factor 50 is a waste of time. Sorry to put a dampener on the risks of cycling in the nice sunny weather; just be careful.