Editor’s note: Cindy Hoyt is The Beachcomber’s occasional humor columnist — just don’t call her occasionally humorous.

If you’ve been alive recently (or read last week’s Beachcomber), you know that sun exposure can damage skin both long- and short-term.

I’ll bet you’d be surprised at how often you don’t do anything about that! In fact, 30% of teenagers believe they’re invulnerable to everything — including solar radiation — so they don’t even use sunscreen. The moral of this story is that if you’re a teenager, don’t be 30% of teenagers.

No matter your age, the top three things you can do to protect your skin are:

1: Get a mom with great skin and inherit her genes.

2: Never drink anything but water. Not even margaritas! Not even with extra ice!

3: Go indoors and stay there for the rest of your life, including retroactively.

These things are really hard, so you’re not going to do any of them. (I myself couldn’t do #1 for more than ten minutes.) The only alternative is self-inflicted behavior modification, inspired by this tale of the Old West:

When I was a young ‘un who believed my dating options would expand relative to the bronziness of my tan, I laid in the sun all summer long. Little did I know I was igniting a range war between my skin and a vicious gang of ultraviolet radiation.

Headed up by the Sun-Damage Twins, UVB (alias The Carcinoma Kid, who had a record of sunburns as long as your arm — on your actual arm) and his hotheaded brother UVA, they snuck up on me minute by minute until my body turned bright red. I lit out of there fast. When the red turned to brown I thought the heat was off, but soon afterward my epidermis staged a walkout.

No matter where I went — the mountains, a Hole In the Wall, February — the Twins got stronger and meaner. I needed a bodyguard.

The next three letters you need to meet are SPF, a rating system designed to let you know how long you can stay in the sun without burning. If your untanned skin gets pink after 20 minutes of sun exposure, that’s your base number. Theoretically, sunscreens with an SPF of 20 extend your time by that multiple: 20 minutes x SPF 20 = 400 minutes, or 6.66 hours total. This should be super-easy to remember if you already associate 666 with burn victims.

“But Cindy,” you wail, “there are a hundred and fifty thousand million sunscreens on the market. Can’t I just buy an SPF 2000 and call it good?”

Nope. SPF numbers only apply to UVB, or sunburn, rays. To head off those dastardly UVAs you’ve got to get out the magnifying glass and (sigh) read the ingredients list.

“Aaaaggghhh!” you exclaim. (Do you often exclaim at newspapers? I do.)

To which I say, “Don’t be afraid of ingredients! Just look for the words “broad spectrum” and either zinc oxide, titanium dioxide, or avobenzone (alias Parsol 1789, alias butyl methoxydibenzoylmethane). And introduce yourself to New Kids on the Sunblock like helioplex and mexoryl/avobenzone. They hold up longer than some, and are good at scattering the rays that do ultra-violence to your skin.

Remember several paragraphs ago when I slipped the word “theoretically” under the base-number fence? You’ll only get full protection from all these “zones” or “anes” or “ides” if you really ladle them on. Practically no one uses the recommended amount, which is a full ounce (aka a Utah shot glass).

If you thought a Utah shot glass was a thimble, just spread on enough lotion that it stays white until absorbed. (Those bottles on the sale rack look a little better now, don’t they? Especially since you must re-apply every two hours, which I found out the hard way is a real thing instead of a corporate profit-generator.)

You must be wondering, “How can I get a date if I’m covered head to toe in butyl methoxydibenzoylmethane?” Good question! I’ll try to get back to you by Rainvember.

Now that you’ve calculated how long it takes you to burn in direct sunlight, you need to understand your risk from indirect sunlight. These numbers will help you brace for stealth attacks:

• Cloudy day: 80% of burning rays still hit you, as crazy as that sounds.

• Dog-paddling: 50% of said rays penetrate the water; the other 50% bounce off the surface and burn your nose.

• Shady spot on the sand: 50% reflects badly on you.

• Shady spot on the grass: 25% reflection; better, but still not good.

• Shady spot on the snow: Up to 90%, so don’t forget to pull the wool over your eyes.

• Side window glass in cars: Your windshield is treated, but 35% of rays hitch a ride through closed side windows. You’ve probably figured out the percentage on open side windows.

• Wet T-shirt: 20-30% potential skin damage.

• Wet T-shirt removed during contest: 100% damage to skin, 94% damage to self-esteem.

The foregoing is an excerpt from Cindy Hoyt’s book “Tansmania.” It is available on Amazon, but take care not to wind up on an island south of Australia.