Drownings, heatstroke, dangerously low salt levels; like it or not, these are all threats when we enter the national parks in the summertime. With a little common sense, and awareness of your surroundings, you can ensure your park vacation will be a great one.

In recent weeks there have been several tragic outcomes for both park visitors who possibly didn’t respect their surroundings, or anticipate conditions, as much as they should have.

* At Cape Hatteras National Seashore in North Carolina, a man got caught in a rip current while swimming at Ocracoke Beach. By the time rangers arrived, the man was about 300 yards offshore. When two rescuers, wearing life vests, managed to swim out to him, he was face down and unresponsive. Efforts to resuscitate him were unsuccessful.

* At Buffalo National River in Arkansas, a visitor used questionable judgment when jumping off a 40-foot bluff into the river. According to bystanders, the man landed face first and didn't resurface. Because of high water flows, search-and-rescue teams were not able to find and recover the Texas man’s body until two days later.

* At Big Bend National Park in Texas, a 25-year-old geologist was found dead after failing to return from his field trip on schedule. While officials did not initially pinpoint a cause of death, they suspected a contributing factor could have been the unusually hot weather that produced daily high temperatures near 110°F.

There also have been victims of heatstroke at Lake Mead National Recreation Area, drowning victims at Yosemite National Park who were swept over towering waterfalls, and even a somewhat rare case of a hiker at Grand Canyon National Park who was suffering from extremely low blood sodium levels, a potentially fatal condition stemming from drinking large amounts of water, perspiring heavily, and failing to eat enough foods to maintain blood salt levels.

The hiker reportedly drank large amounts of water, but had eaten very little food. This, coupled with the expected increased perspiration while hiking in hot temperatures, lead rangers to believe this visitor was suffering from a potentially life-threatening condition due to low blood sodium levels known as hyponatremia. Responding via helicopter, ranger/medic Brian Bloom utilized a portable blood chemistry instrument (iStat) to confirm his suspicions and begin appropriate field treatment. Due to the serious nature of the man’s condition and the lack of nearby landing zones, he was helicopter short-hauled with Bloom from switchbacks in the Redwall to the North Rim helibase. He was then placed inside the helicopter, flown to the South Rim, and taken from there to Flagstaff Medical Center. He is expected to recover.

Sadly, in the weeks and months ahead there will be additional cases of park visitors being harmed and even killed by events that could be avoided with a little preparation and common sense. If you are heading out into the parks, lakeshores, and seashores this summer, take a little time to recognize possible dangerous situations.

* If you’re swimming in a national seashore, pay attention for possible rip currents as well as waves that might be larger than usual due to storm systems. Check with lifeguards and or park visitor center staff for the latest ocean conditions. Even the national lakeshores on the Great Lakes can generate rip currents, so be careful there as well.

* If you want to cool off in the rivers and creeks of a national park such as Yosemite, Great Smoky Mountains, Shenandoah, or Glacier, be aware that swift currents can quite easily knock you off your feet and send you downstream into hazardous conditions or over waterfalls. While climbing relatively small waterfalls in parks such as Great Smoky or Shenandoah might seem the perfect way to cool off, the rocks can be slippery, causing you to fall and possibly injure yourself or worse.

* And if you’re hiking in one of the Appalachian national parks, keep an eye on the trail in front of you. These parks are home to snakes, such as the poisonous Northern Copperhead and even some Timber Rattlesnakes, and the last thing you want to do is step on one as you're hiking on the trail.

* If you find yourself hiking in one of the Southwest’s national parks, such as Canyonlands or Grand Canyon, be sure to carry enough water to get you through the day as well as salty snacks to both keep up your energy and maintain blood salt levels. Also be sure to dress appropriately, with a wide brimmed hat, quick-drying and light-colored clothing that will reflect instead of absorbed the sun’s heat, and wear sunglasses and sunscreen to protect your skin.

* Don't underestimate your setting. At Yosemite National Park, where the average June high temp in the Yosemite Valley is 81 degrees, it was a record 105 degrees in the Yosemite Valley on June 8! Definitely a good day to take it easy and increase your fluid intake.

* When heading off on a backcountry hike, it’s a good idea to check with rangers on trail conditions. Were there any recent storms that might’ve washed out bridges, or raised water levels that might make stream crossings dangerous? In parks such as Glacier and Yellowstone, has there been any recent bear activity in areas where you’re heading? Speaking of bears, do you have bear spray?

* And when boating, be sure you and everyone with you is wearing a U.S. Coast Guard-approved life jacket. These lifesavers do you little good if they’re floating away from you as you flail in the water.

* If you’re planning a day-long hike, or a longer multi-day excursion, into a national park, leave details of your itinerary with friends and family and let them know when you plan to return.

* Boulder and cliff scrambling can be fun, but if you're not as skilled as you think you are you could find yourself stuck; going up is always easier than coming back down.

* Head out prepared. If you plan on hiking most, or all, of the day, take a little extra food, plenty of water, rain gear, matches, good maps, and a First-Aid kit.

All these precautions might sound obvious, but it’s been demonstrated that when visitors head to national parks for their vacations, they sometimes relax a bit too much and overlook the obvious.