While San Diego County's environments are generally gentle and safe, there are some common safety considerations that all hikers should be aware of while out on the trails. As with all recreation activities, preparation is a crucial element to ensure not just safety, but the most enjoyable experience possible. To that end, your choices regarding clothing, footwear, hydration, sun protection, and encountering wildlife will go a long way to assuring a great experience.

Hydrate!

Although the climate in San Diego is considered among the best in the world, temperatures extremes do occasionally occur, especially in the inland regions. Summertime temperatures routinely exceed 90 degrees in the inland valleys and mountains, and have been known to exceed 120 degrees in the deserts! Even if it seems relatively cool, bring more water than you think you can drink. In addition, sweating causes your body to lose electrolytes, which can impair muscle function and other important body functions. Drinking electrolyte-rich beverages and consuming salty snacks along with water can help your body remain hydrated.

Sun protection

Many of the county's trails offer little to no shade, which can lead to sunburns and other heat-related injuries. Hikers can stave off the sun’s harmful rays by wearing wide-brimmed hats, light-colored, loose fitting clothing, and sunscreen.

Terrain

Most of the trails presented here are well-maintained with few physical hazards. However, even on well-traveled trails, you may encounter rocky, sandy, or loose soils on steep terrain that can create treacherous footing. We recommend sturdy hiking shoes, trail-runners, or hiking boots instead of tennis shoes or other casual footwear with minimal tread. We also suggest the use of trekking poles, which can improve balance and help hikers navigate difficult terrain.

Dangerous Plants

While most of the plants in San Diego are harmless, there are a few special exceptions:

• Poison Oak, a deciduous vine that prefers cool shade along watercourses and north-facing hillsides, can cause severe allergic reactions when touched. Poison oak leaves grow in clusters of three, range in color from bright green to dull red, and they have a waxy, glossy surface. Remember the adage: Leaves of three, let it be!
• Desert hiking may bring you in close contact with a variety of plants whose thorns can puncture skin, clothing, and sometimes even footwear! If you plan to hike in the desert, be especially cautious to avoid contact with cacti, ocotillo, cholla, catclaw, and mesquite.
• Although rare, stinging nettle occurs on some of the San Diego mountain hikes. This stream-side plant contains many hollow, stinging hairs along its leaves and stems. If you brush against this plant, you will know it!
• Poodle dog bush, an even rarer semi-succulent plant, is a fire-following species that has a rank, musky odor similar to skunk spray. Like poison oak, poodle dog secretes a severe skin irritant that causes painful rashes and sores. You'll find it at high elevations where recent fires have occurred.

Wild Animals

Animal encounters are a thrilling experience. Few things are more memorable than crossing paths with a mule deer or a flock of wild turkeys. However, San Diego's environs do contain a few creatures you will want to watch out for:

• Rattlesnakes live in all parts of the county from the coast to the desert. Rattlesnakes are shy, retiring creatures that want to avoid you even more than you want to avoid them. Their rattles will warn you when you get to close, and they generally only attack when cornered. Rattlers do become more aggressive during the spring when their long hibernation leaves them hungry and irritable, but if you give them a wide berth, you will have no trouble.
• Mountain lions are a very rare predator that are present throughout the county as well. Most hikers spend their entire life in the backcountry without ever encountering one, but there is always a slim chance that you may see one. If you encounter a mountain lion, do not run, as this triggers a predatory response. Keep your children close and do your best to appear as large and as loud as possible. Like a common house cat, mountain lions hate noise and aggression and will usually retreat to a quiet, safe space. Traveling in groups also reduces the chances that you will encounter a lion.
• You may encounter other predatory mammals such as bobcats, foxes, and coyotes, but these animals are equally shy and want very little to do with humans.