Some of us may already be taking advantage of the early days of summer, not to mention try to cool the body from excessive heat by swimming. Just don’t forget about sunburn!

People have worshiped the sun for a thousand of years. But only in the last century have people worshiped the sun by baking themselves in it to a golden tan – or, as may be more often the case, to an angry red burn. But the sun can do much more damage than simply give you painful sunburn. Dermatologists say that prolonged exposure to sunlight causes brown spots; red, scaly spots; and drying and wrinkling. Worst of all, it can cause skin cancer.

According to The Home Remedies Handbook: although few things can penetrate the skin’s outer layer (stratum corneum), the sun’s ultraviolet rays easily pass through this layer and damage the cells and structures beneath. Ultraviolet light comes in two varieties: ultraviolet A (UVA), the so called “tanning rays,” which do not cause sunburn (except at very high doses), and ultraviolet B (UVB), the “burning rays.” UVA rays can pass through window glass while UVB cannot. Both types penetrate the outer layer of the skin and cause damage.

Ultraviolet rays that can pass through the stratum corneum cause pigment-producing cells called melanocytes to produce brown pigment (melanin). This is the skin’s effort to protect itself from the invading rays and prevent further damage to skin structures. How much and how quickly the melanocytes can produce the pigments depends largely on genetics. Dark-skinned people can readily produce melanin, while light-skinned individuals, especially of Northern European ancestry and Orientals, don’t produce it well or produce it in blotches that appear as freckles. These people can’t tan no matter how hard they try and tend to be “quick fryers,” readily burning even with mild sun exposure.

If your skin doesn’t produce the protective melanin pigment well, or if you’re overexposed to the sun before the pigment can be manufactured and dispersed, the ultraviolet rays damage the epidermal cells. “The sun’s rays actually cause the skin cells to die,” says James Shaw, M.D., chief of the Division of Dermatology at Good Samaritan Hospital and Medical Center and associate clinical professor of medicine at Oregon Health Sciences University, both in Portland. “Even if you develop only a mild redness, you’re killing the top layer of your skin just as you would with a thermal burn from touching something hot.”

Damage to skin cells is more prevalent among fair-skinned people, and the immediate effect is sunburn. Overtime, the effects can be much more serious-blotchy brown spots and even skin cancer.

Ultraviolet light can even damage the dermis, the layer of skin that gives your skin its shape, texture, strength, and elasticity. Sunlight breaks down the thick, strong tissue structure of the dermis, rendering it weak, thin, and less elastic and making it appear wrinkled and saggy.

You’d probably never expose yourself to a sunburn again if you could see the dramatic damage to your skin under a microscope-cells are shrivelled and dead; formerly thick, red bundles of connective tissue have been ground into a gray smudge; thin-walled, superficial blood vessels are dilated and may be leaking fluid; and DNA sequences, the “software” that tells the skin how to repair and replicate itself, are damaged, causing the skin to produce abnormal precancerous cells and, in some cases, cancerous cells.