Ahh, summer. Long, warm days, outdoor activities galore, and—ouch!—bothersome pests, burning sun, and unexpected bumps and bruises (yes, you did have to dive for that volleyball). But don’t sit on the sidelines in fear of mishaps; instead, swing into summer with natural first-aid advice tailored to the season.

At the beach

Sunburn. You’ve likely endured sunburn at least once in your life, but kids and young adults are in the greatest jeopardy of suffering from a burn’s long-term effects. According to a 2011 review published in Pediatrics, at least 25 percent of sun exposure—and up to 80 percent—occurs before age 18, considerably increasing skin cancer risk later in life.

Prevention is, as always, your first defense. Liberally apply a broad-spectrum sunscreen (one that protects against UVB and UVA rays) with an SPF of 30 or higher. Choose one with mineral ingredients like zinc oxide and titanium dioxide that “block” harmful rays, rather than sunscreens that contain chemicals such as oxybenzone or octinoxate, which can disrupt hormone balance and cause allergic reactions. And remember, no sunscreen is truly waterproof—despite what the label says—so reapply every two hours or after swimming or sweating excessively.

What if you do get sunburned? Aloe vera remains the tried-and-true cooling and anti-inflammatory burn remedy, says Sheila Kingsbury, ND, chair of the department of botanical medicine at Bastyr University in Kenmore, Washington.

Dab sunburned skin with an aloe-soaked cotton ball at least twice per day, and take cool or lukewarm showers (not scorching hot) to further reduce inflammation. Got a tube of aloe languishing in your medicine cabinet since last year? Toss it. Kingsbury says it’s best to buy a new aloe gel every year and keep it in the refrigerator to maintain its freshness and healing properties.

Also, rub sun-kissed skin with a thick lotion containing antioxidant vitamin E to reduce long-term skin damage, say experts at the Linus Pauling Institute at Oregon State University. Choose an alcohol-free lotion to avoid further irritation.

Jellyfish sting. Although sting severity largely depends on the species, tentacles from sea nettles, one of the most common and least dangerous jellyfish found on the Atlantic and Gulf coasts, cause an irritating rash and a searing, throbbing sensation. Jellyfish stings can also trigger allergic reactions—especially in people sensitive to bee stings.

“Most types of jellyfish stings respond well to vinegar,” Kingsbury says. According to a study in The Medical Journal of Australia, vinegar’s acetic acid prevents the further release of microscopic nematocysts—venom-filled structures on tentacles. Remove any tentacles, and then soak the affected area in a 1:1 white vinegar–seawater solution for 30 minutes. (If no vinegar is handy, just use seawater.) Don’t rinse in fresh water; the pH change from seawater to fresh water hastens venom release. Resist the urge to rub the sting with a towel—that’s also likely to discharge more venom. And despite the urban legend, fresh urine won’t help a jellyfish sting and may make it worse.

Most important, if you or a friend suffers a jellyfish sting, watch carefully for anaphylactic symptoms like shortness of breath, abdominal pain, muscle cramps, hives, or vomiting. If any of these occur, call 911 or head to the hospital.