Freckles are caused by an irregular pigmentation of the skin. Material called melanin is normally present in an even manner below the superficial skin cells. This reacts with sunlight to produce a protective tan and so prevent burning. But sometimes after sun exposure, instead of the tan being even, it is irregular, and brown spots appear between the white areas of non-pigmented skin.
Blonds, redheads, brunettes and fair complexioned people are more likely to suffer with freckles. These are also more likely to burn on hot days.
It’s good to remember that exposure to the sun is the way they will be aggravated, so the more sunbathing, the worse they will be. Wearing adequate protection when outdoors in summer is good advice. Broad-brimmed hats, umbrellas, swimming for short periods rather than very long periods, wearing ultraviolet screening lotions and creams will all assist.
There are many effective commercial lines, such as Sunsense UV Ultraviolet cream, Blockout, Uvistat and many others. Reapply often and after each swim, for many are soluble and wash off in the water. Ideally use factor 15 strength if the skin is very white.
If the person is embarrassed by their freckles, these will give a temporary masking effect that may make the person feel a bit better. If very troublesome, laser removal is available.