Natural Science Forum / Biology / Biology / February 2008

I assume by 'ampoules' you mean blisters.

Blisters indicate a severe (second degree) sunburn.  It's severe
sunburns like this that are most likely to result in skin cancers,
usually many years later.

If you are light-skinned and inclined to burn, you shouldn't go out
in strong sunshine, especially the hours around noon, without some
protection, either a sunblock cream or clothing.  Just how strong
sunshine is depends of course on the time of year and distance from
the equator.  Note that UV penetrates cloud cover to some extent
so you can get a sunburn even when it's overcast.

If you are able to tan effectively, you should do it slowly, to
build up the protective pigment.  Start with short exposures in
mornings or afternoons.

Once you've got the sunburn there isn't much you can do but wait
for it to heal, although cool water and some topical creams can
help ease the discomfort.

On a cellular level, cells are destroyed by the action of the
ultraviolet light in sunlight.  Shorter UV wavelengths damage
DNA and either kill the cells outright, or cause them to kill
themselves (apoptosis) due to irremediable DNA errors.  Some
damage (mutations) may persist in living cells, which may
ultimately result in cancerous transformation.

You should check exposed areas, especially those that have suffered
severe sunburn occasionally for suspicious lesions, especially as
you get older.  Sun-induced skin cancers are seldom lethal, but
you do want to get them treated before they cause disfiguring
damage.

I hope this helps.