SUNBURN

Sunburn tops the list of beach perils. A single baking can damage the skin enough to cause skin cancer years after the burn. Fair-skinned people are especially at risk.

PREVENTION

Don't bake. Tan gradually, if you must. Limit exposure during the first few days of the season. Avoid midday sun. Always use sunblock or sunscreen with a sun protection factor of at least 15. Fair-skinned people should use at least SPF 30. Look for these effective chemicals among the contents: paba esters, cinnamates and benzophenones. Overprotect infants. Invest in a floppy hat and beach umbrella.

TREATMENT

Cool baths and wet compresses relieve pain. Elevate burned arms or legs. Drink plenty of water. If you have a rash, chills, fever, weakness, dizziness, nausea or your eyes burn, seek medical aid immediately. Likewise if blisters become infected. Be on guard for signs of heatstroke - red, hot and dry skin, extremely high temperature, no sweating, rapid pulse, disorientation, convulsions and unconsciousness. If you suspect heatstroke, seek medical aid immediately - call 911. Body temperature must be lowered at once. Wrap the individual in cold towels; spray with hose if necessary.

JELLYFISH AND MAN-OF-WAR

Jellyfish give swimmers a short-term, irritating sting. Far more severe is the Portuguese man-of-war, which is not a jellyfish but looks like one. The man-of-war, indigenous to the Atlantic, is purplish in color and releases an acidic venom that can cause great pain, shock and even death. Swimmers may brush against such creatures and their trailing tentacles. The man-of-war's acid can remain toxic even when the creature has washed ashore.

TREATMENT

Rinse skin with sea water, not tap. Remove remaining tentacles with gloved hands or a fork. Don't handle them. A jellyfish sting is generally a short-term irritant that can be treated with a topical anesthetic such as Solarcaine, Foille or Dermaplast. Man-of-war burns may be neutralized with full-strength vinegar, rubbing alcohol or a paste made of plain meat tenderizer. (Because children have tender skin, do not apply meat tenderizer to the sting for longer than 10 minutes.) Man-of-war victims must be watched closely for signs of shock. Because it is not always possible to identify the kind of jellyfish, the stronger man-of-war antidotes can be used just to be on the safe side. Victims should be kept out of the sun until their pain subsides.

LIGHTNING STRIKES

Lightning is the second-biggest weather killer, next to floods. More than 8 million strikes a day occur worldwide, most in tropical areas or near water. The most deadly strikes occur in the afternoon.

PREVENTION

Take the first rumble of thunder as an early warning. Run from the water when you see the first bolt. Get in a car or a secure building. Lightning seeks the tallest objects, so don't be the tallest object on the beach and don't wait out the storm under a tree.

TREATMENT

Few people survive a direct lightning hit, because the bolt is hotter than the sun. Typically victims of an indirect hit will be knocked to the ground, possibly unconscious, sometimes burned. Lightning victims do not retain an electrical charge so they may be touched. Administer CPR is necessary, stop any bleeding and call 911.

SHARK BITES

Most sharks are not dangerous and will leave swimmers alone. On average, fewer than 75 shark attacks and 10 fatalities are reported worldwide each year. The deaths occur when people surf, swim or scuba dive where there are large sharks, such as the great white. Florida waters are populated by much smaller, less-aggressive sharks, typically, juvenile blacktip and spinner sharks.

PREVENTION