A day at the beach: cancer, dehydration, insects, and more.

Do you a) grab a sleeping bag and crawl into a 41-degree cave and spend the day snoozing; b) crank up the air-conditioning and watch the Sox on NESN; c) turn on the overhead fan, sit on a shady porch, and get quietly drunk on rum punch and Acapulco Zombies; or d) take off most of your clothes, drive through heavy traffic to a place where there’s no shade and nothing to drink, and lie on crushed rocks next to a large reflecting body of non-potable water?

Strangely, many folks answer “d.” Of all the peculiar life choices to which people fall victim, beach-going is among the most difficult to comprehend. Smoking, drinking, heroin addiction, compulsive gambling, and even karaoke all at least have their upsides. Where’s the fun in being too hot?

Face it, several dozen eons ago our aquatic evolutionary ancestors grew legs, and pretty much the first thing they did was scramble out of the ocean. The fact that life on earth survived and produced species as diverse as the garden slug and the pope tells you that those fledgling tetrapods didn’t linger on the sand. Beaches are made of pulverized minerals, sort of an inorganic-chemistry field experiment incapable of supporting all but the most rudimentary life forms, and parthenogenesis will take you only so far. To evolve properly, life moved inland.

To this day, the beach, our most distant racial memory, remains inhospitable. Going to the beach is like taking a trip to the end of the earth, which, when you think about it, it is.

And there’s proof — lots of it — that beach-going in summer is hazardous to your health. Take sun poisoning. The phototoxic effects of ultraviolet rays is a medical reality, and now that unchecked industrialization, flatulent cattle, and unbridled SUVs have managed to strip away the atmosphere’s natural defenses, the UV bombardment is all the more lethal. Direct exposure to the sun results in the formation of bullae — or fluid-filled blisters, to use picturesque non-medical terms — under your skin. You may even turn purple and pass out.

Longer term, there’s skin cancer. Have you ever seen the transitional results of topical chemotherapy to treat incipient melanoma? Imagine what your face would look like if it were dragged behind a Chevy for three miles over rough asphalt. Fun in the sun, my ass.

Then there are the aesthetic negatives of tarrying at the shore. Glare from the sun, which is intensified when it bounces off the water, guarantees a day of squinting discomfort or cornea damage. Sand, fundamentally flecks of dead earth, sticks to your sweaty body and chafes any adjacent skin surfaces. It blows into your eyes and mouth and pollutes your food. Yum — soft-serve ice cream with silicate jimmies.

Sure, you can slather yourself with high-SPF lotions, try to anchor a giant umbrella in the sand for shade, and wear half-inch-thick No. 3 Green sunglasses, but how is that a “relaxing day at the beach?” That’s like suiting up for a relaxing afternoon on the surface of the moon. Incidentally, sunscreen doesn’t necessarily prevent skin cancer.

Perhaps there are climates where diving into the surf for relief is so much fun it compensates for some of the above. Surely those beaches will never be confused with New England’s, where the water, even in high summer, can be shockingly cold. Still, it’s tempting to wade in just to wash the grit and beach-slime off your body momentarily.

Or to escape being devoured by greenhead flies, sand fleas, or other ravenous lower creatures desperate to eke out an existence where neither plants nor mammals can thrive. The water itself hosts a wealth of similar treats from poisonous jellyfish to great-white sharks, but that’s another story.

Finally, there’s filth. The beach may look clean when you squint, but check it out at low tide when all manner of stranded marine life dies and decomposes. And what’s that outflow pipe over there dumping in the ocean? At best motor oil and cigarette butts from storm-sewer run-off; at worst raw sewage.

Photodermatitis, second-degree burns, cancer, skin abrasion, insect bites, gastroenteritis, keratitis, dehydration, thermal shock, and a bully kicking sand in your face. A day at the beach is not, as they say, a day at the beach. Besides, you probably look like a punk in a swimsuit.