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It's Summer—Here's How To Avoid Health Hazards In The National Parks


Whew! Big, but not poisonous. Be aware—and away—from all kinds of dangers and your summer national park trip will be memorable for all the right reasons. Photo by Randy Johnson

Quite a topic, eh?

Everyone has seen some expert pontificating on the long list of common sense safeguards that somehow common folks don’t have the sense to grasp. But it's true—the ultimate item you’ll want to carry isn’t in your pack, it's in your head: knowledge!

Let’s start with a less than common conception. The best approach to looking out after yourself may be to safeguard others.

First case in point—kids. Hiking is a wonderful way to give young people a love of the outdoors, an enjoyment of physical fitness and exercise. Do it right, and the lesson may take, and you may have a safer summer.

Even if you have sophisticated child-carrier pack, avoiding tree limbs and other obstacles is step one. But children also fall asleep in these packs, so in advance of a hike, have a way to stabilize a sleeping hiker’s head.

And don’t forget a secret that applies to not just kids. The national parks in summer mean a range of experiences from Biscayne National Park to Denali. A cold mountain rain can mean hypothermia one place—refreshment the next.

Children in backpacks aren’t active, so if it’s cold, carry hot drinks or soup in a Thermos. Urban-style outerwear won’t work. There is no substitute for effectively layered, high-quality clothing. If it’s hot, those carriers are like sleeping bags. Cool, wicking clothes are a must—in advance!

Remember, children who have a bad experience will not be enthusiastic about parks in the future (a nationally significant issue). Focus on comfort and safety. Think about others—not yourself—so bring it all—sunscreen, hats, insect repellent, topical anesthetic for bug bites or sunburn—ingredients for a successful family (or any other) hike.

Basics of What to Carry

Let’s get it over with! Any small backpack or fanny pack should have:

• a water bottle or hydration system

• a snack or extra food

• spare clothing and other protective items (raincoat, sunscreen, insect repellent, sunglasses, and a hat.)

• a small first-aid kit (bandages, antiseptic, extra-strength aspirin/acetaminophen, moleskin for blisters)

• the recommended hiking maps

• any trail permits or registration requested by park headquarters

The Basic Overview

Clothing isn’t a snake or a bear—but the basics (the things you can control) will serve you well when everything else goes wrong.

Any summer activity may dictate shorts and T-shirts, but be prepared for the worst weather the season and place can deliver. Luckily, the latest trail shirts and pants (the latter with zip-off legs) are virtually weightless, dry fast, and are even sun protection formula (SPF)-rated.

The best choices for outer garments are waterproof and breathable jackets and pants made of synthetic fabrics. A cotton T-shirt can be cool—and freezing after a rain. A higher-tech fabric can be warm even when wet. A light pile sweatshirt is a great summer over-garment.


How many evacuees have you seen wearing flip-flops? Believe me, rangers could bend your ear.

Wear a sturdy pair of walking or running shoes—but on even easy hikes with rocky footing—wear at least light hiking boots. The newest-generation boots are lightweight and relatively inexpensive. Want proof? Check out this article.

Weather Dangers

If you have the right clothes, you’ll be able to weather the number one outdoor issue—weather.


Surprise, this winter hazard can occur at any time of year—at temperatures well above freezing—especially in our loftiest national parks. It's all about the dramatic cooling effects of wind and rain. To prevent it, stay dry and protected with the right clothing—especially a hat, since up to 70 percent of heat loss can emanate from your head. When you stop for a rest, put on a hat before you get chilled.

Heat stroke and heat exhaustion

Be sure to carry and drink plenty of fluids, especially if you’re sweating heavily. Avoid hiking during the hottest part of the day. If you feel dizzy and drained, heat exhaustion may be the culprit. Relax, drink fluids, and let your body recover. Heat stroke is a more extreme—and dangerous. Rather than being damp and drained, you’ll be dry and feverish, signs that the body has given up the attempt to cool down by perspiring. Immediately drink water and cool off with cold, wet compresses—and, seek medical attention.

(Tip: Click "Search" on the Traveler Nav Bar for articles about your park, especially if it's a Western desert park. Our feature articles have excellent insight into local conditions and often contain specific tips on when to hike. For an example, see this Discriminating Explorer on Canyonlands and Arches national parks.)


A hiker’s major summer danger may be lightning, especially on exposed mountaintops in prone areas. At the first rumblings, move off ridgetops and seek shelter in a group of smaller trees. Rest in a low, dry area (but not a gully or near a pond, where water can conduct the current). Avoid overhangs or small caves where ground current might pass through you. To further insulate yourself, crouch low or kneel on top of your pack or sleeping pad.

Trailside Pests


Be cautious around fruit and flowers, and be on the lookout for nests hanging from limbs, in hollow trees and logs, or on the ground. And don’t entice them with perfume or scented body products.

Most stings are minor and easily treated (unless you’re allergic). Simply scrape an imbedded stinger out with a knife blade. (Don’t squeeze it out, which releases even more venom into your bloodstream.) A paste made of water and unseasoned meat tenderizer that contains papain (a papaya enzyme) can neutralize bee venom; baking soda paste does not.

If you’re allergic to bee stings, an over-the-counter antihistamine that contains diphenhydramine (such as Benadryl) can help control mild allergic reactions. If you know you are allergic to bee stings, always carry an epinephrine syringe bee sting kit—and be sure your companions know where it is and how to use it.


Many parts of the country are favorite habitats for ticks that can carry Lyme disease and Rocky Mountain spotted fever—potentially deadly diseases. Both diseases can take up to two weeks before symptoms develop. Among the signs are arthritis-like joint pain, high fever, and/or a bulls-eye rash.

The best defense against ticks is three-pronged: First, use a tick and insect repellent that contains N, N-diethyl-3-methylbenzamide, more commonly known as DEET. Second, whether you use repellents or not, wear long-sleeved shirts and long pants and avoid walking through tall grass, brush, or dense woods. Third, frequently check yourself for ticks, especially at night and when you finish a hike. Focus on armpits, ears, scalp, groin, legs, and where clothes, such as socks, constrict the body. You have a good shot at preventing infection if you find them early.

If a tick becomes embedded in your skin, use tweezers to remove it and grasp the head to avoid squeezing toxins into the wound. The tweezers can also be used to pull out any remaining mouthparts. Then clean the wound thoroughly.


The best defenses are to use insect repellent, keep food and garbage covered or stored elsewhere when picnicking and camping, and cover your body. The newest trick is to reduce the use of chemicals and buy and wear the new Buzz-Off treated clothing, the first bug-banning technology to get the EPA’s nod.

Mosquitoes and gnats are prevalent on cool mountain evenings. Again, the Buzz-Off garments are effective, or use repellent with DEET.

Poison ivy, poison oak, and poison sumac

Remember, “leaves of three, let it be.”

If you realize that you just touched one of these poisonous plants, remove and isolate contaminated clothing until it can be washed at home. Flush the affected skin with water but no soap—your skin’s natural oils will protect you temporarily. Preventive creams you can apply before exposure are also available.


Serpents rank high on the list of fears in parks, but these animals play their role in nature. The best way to avoid being bitten is to be observant—and be able to recognize poisonous snakes before they can bite. Rattlesnakes and copperheads are generally heftier than nonvenomous snakes and have triangular or arrow-shaped heads and vertically slit pupils (versus tube-shaped heads and round pupils for nonvenomous snakes). Don’t reach blindly behind logs and rocks, inspect wooded sites before you sit, and watch where you step. Luckily, of the 20,000 people bitten by venomous snakes annually in the United States, fewer than 15 die.

If bitten, be able to report what kind of snake bit you. Observe your wound: The bite of a pit viper includes two or more prominent fang marks, while a nonvenomous snakebite usually leaves two rows of indentations and no big holes. Immediately remove all watches and rings that may cause constriction from swelling. Do not make incisions with a knife or try to suck out the venom. Do not use tourniquets, cold water, or ice packs, which increase the possibility of gangrene. Instead, loosely splint and immobilize the affected limb, and mark on the victim with a pen the time and spread of swelling. If you are within 20 minutes of the trailhead, carry the victim (or permit the person to walk slowly, with frequent rests) to a vehicle for immediate transfer to a hospital. If hiking alone—not necessarily a good idea—walk as calmly as possible back to your car for help. Hikers who are far from a trailhead should send a companion for help and wait for emergency personnel to return with antivenin.


Most of the time, a backcountry glimpse of a bear features its bouncing butt bounding away. If you have a sudden encounter with a nearby bear, especially a mother with cubs, steadily and calmly back away. Leave the area. Do not turn your back on the bear. Do not run or climb a tree, since this may provoke a chase—and you cannot outrun a bear. Stand your ground if charged; bears often bluff. In the West, use bear bells to announce your presence—and carry bear spray and know how to use it.

Problematic locations for bear encounters are popular campsites, where marauding bears forage through garbage. There they can be aggressive, especially if you approach while they are enjoying food. Stay away. The best defense against such encounters with bears—and with skunks and other animals, even mice—is to keep your food away from camp. Safely hang bagged food by tossing a rope over a tree limb, tying on your food container, running the food into midair away from the trunk, and tying the other end where you can reach it.

Waterborne pests

An invisible animal threat is a microscopic one, giardia lamblia. Hikers have even contracted Type A hepatitis from drinking untreated water in the “wilderness.” Unfortunately,even pristine-looking streams may contain these and other disease-producing agents. All hikers should carry water from treated sources, carry commercially bottled drinks, or treat the water they use. There are low-tech solutions, but just carry a portable backpacker’s water purifier. Do not attempt to disinfect water with halazone, chlorine, or iodine.


When you start talking about objective hazards, there’s no more prominent death trap than the waterfall. Really, how many people do you have to read about falling from these beautiful sites before you get it—stay in the viewing area! Do not step on the slick stuff!

Which frankly, brings us back to the “almost” obvious. Without sounding melodramatic, incidents involving children and pets are invariably at the top of the list of precipitating factors for accidents.

Children and Pets

When you add waterfalls to the mix—kids and pets reflect the dictate to watch out for others and a lot takes care of itself. Watch children and pets closely to avoid being drawn into trouble by trying to keep them out of it.

Many national parks prohibit dogs because their territorial instincts can complicate life for wildlife populations already trying to survive in shrinking natural areas. While out of sight of the their owners, dogs that run free dig up animal dens, even kill wildlife, and leave their scent (not to mention piles of pooh, sometimes on the trail).

There are real virtues to using a leash—just read this tale of winter canine woe. And the benefits of close control can extend to physically restraining children as well. I’ll never forget the father I saw walking his child down from the Matterhorn with a leash attached to a mini-climbing harness.

Many dogs, and children, get lost in wild areas, injuring themselves and exposing searchers to hazards. The only person I’ve ever known who fell off a waterfall, (and luckily survived), was trying to save his dog.

If there is a leash law at the park you visit, please obey it. Peruse your park’s rules, and talk to rangers before you set out. Any list of “rules” is all about “circumstances”—and no one is better at clueing you in to what’s what where you are—than the ranger you smile at on the way into the campground.

It may be time to return to the real insight here—many “health” problems in the parks don’t necessarily start with you. Turns out that looking out for the “other guy”—whether they’re kids, dogs, comrades or fellow campers -- is a great prescription for staying out of trouble.

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This is horrible advice: "If a tick becomes embedded in your skin, use a bit of repellent, rubbing alcohol, or a hot, extinguished match to encourage the tick to back itself out." But if you want the tick to regurgitate its stomach contents into you, go ahead.

Anonymous—thanks for the correction of at least part of what we wrote. Your CDC link invalidates the "heat" application and "waiting for the tick to detach"—so I have eliminated that from our story—which also includes exactly what the CDC does recommend. [Must'a snuck in from that antique Boy Scout Handbook I was reading a few days ago... ;-)] So, other readers, please check out the CDC link above for more, including the suggestion that you use tweezers to remove "mouth parts" should any be left in your skin. Again thanks for taking the time to suggest the CDC link.

All very good advice. Finding and promptly removing ticks (from a person or pet) can dramatically reduce risk of infection. Once the tick has been removed, don't discard it. Instead, have it identified. Only certain kinds of ticks can transmit the agents of Lyme disease, babesiosis and anaplasmosis. Other ticks may transmit other infections. The longer the tick is attached, the greater the risk of infection. Physical samples can be sent, or digital images uploaded, for a rapid, confidential, independent and expert evaluation. You can even capture and submit an image from your cell phone, and get an answer before you're back from your hike. For more educational information and help with tick identification, visit

It seems like most people, myself included, just worry about mountain lions but this is all very helpful and more useful advice. Just yesterday I came back from a hike with 6 ticks outside and inside my pants. Thankfully I found them all before any of them set in. Also thanks anonymous and Richard for your links. I will keep them handy.

Richard and Al, thanks for your comments. If you or anyone else wants to recommend mountain lion protocol, please do so. With both links above in mind, try to be relentlessly accurate. I did in fact leave out the mountain lion topic and would love to invite experts or anyone with insightful stories to weigh-in. Did we leave out anything else?

I ended up with Lyme Disease when working in park in the eastern US. I never did find the tick. Maybe it was in my hair or because I'm covered in freckles, I just never noticed an extra spot. Luckily (or unluckily for them) several other rangers had been sick, so as soon as I started feeling weak and I had headaches and sore joints, I got to the doctor as fast as I could. I don't fear mountain lions or bears or anything else big enough to eat me, it's the little bloodsuckers I don't like (gnats included!)

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