For best results, apply sunscreen just after getting out of the shower when your pores are open, which allows more sunscreen to be absorbed. And be sure to lather sunscreen onto the places you wouldn't expect to burn, such as the tops of your feet and below tan lines, Arbin says.
Nothing can sour a beach trip quite like a case of heat exhaustion. Symptoms include feelings of weakness, dizziness and nausea, brought on when the body loses fluids and starts to overheat. If heat exhaustion goes untreated it can turn into heatstroke, which occurs when the body's sweat mechanisms start to shut down, leading to a rise in internal temperature and organ failure.
If you begin to experience any of the symptoms of heat exhaustion, get out of the heat and sun immediately, and start rehydrating with cold water, Arbin says. Avoid sports drinks and soda, which contain sugars and chemicals that need to be digested. Instead, drink plain water, which is the liquid most quickly absorbed into the body, Arbin says.
You can help prevent heat exhaustion by avoiding alcohol (which causes your body to eliminate water more quickly) and by staying hydrated throughout the day. "Thirst is not a good indication of a need to rehydrate," Arbin says. "Because when you feel thirsty, that's an indication that you're already dehydrated. So when people say, 'Wow, I'm thirsty, I better get a drink,' really you're starting to feel the signs of dehydration. So for parents, you need to push the water, you need to push the liquids."
[Read: How to Tan Safely.]
Sand dunes can shift and collapse unexpectedly, leading to burials, bruises and broken limbs. Be careful when exploring sand dunes and don't overestimate their stability, says Travis Heggie, a professor at Bowling Green State University in Bowling Green, Ohio.
Elsewhere on the shore, children – who love to dig holes through beach sand – can find themselves trapped or crushed by tunnel collapse or by stumbling into hidden sand pits or old holes. When digging, keep any hole knee-deep to the smallest person in your group, Arbin says.
And while it's important to let kids be kids, Heggie recommends keeping a close eye on loved ones whenever you visit a beach. Watch out for pre-existing sand holes and take stock of your surroundings. "We don't want to scare everybody," Heggie adds. "Face it, the beach can be a wonderful experience, but dang it, you better have your sunscreen on, and you better be wary of the environment you're playing in."