Many states donít wear helmets for outdoor activities, but awareness is changing. People donít even use them when rafting, unless on the wilder class 4 and 5 rapids, so do ask for one and set a good example! They all supply them, they just donít shout about it. All kayakers use helmets.
Wildlife awareness is important in the national parks. With animals like bears, mountain lions and snakes, you need to inform yourself of what to do in the event of an encounter before you go. The Rocky Mountain National Park, for example, has excellent guidelines. Do not let your children wander too far ahead of you, so that you can keep a close eye.
Temperatures can plummet in some of the national parks, so always carry a sensible layer or two. Hypothermia can be life threatening and happen at any time of year.
Lightning storms are common in some parks, and usually take place on summer afternoons. So best to hike early if you are going high, so that you are descending by the afternoon. If lightning does occur, get below the treeline and stay away from summits or isolated trees. Stay as low as you can and take your backpack off if it has a metal frame in it.
Always be prepared with maps, compass, rain gear, pocketknife, matches and a whistle. And always tell someone where you are going. Most trailheads in national parks have a book you can sign to say where you are going, and how many are in your party.
Flash floods do happen in some of the canyon parks, and waters can rise very quickly. Each national park website always has updated warnings, so keep an eye on this as well as the weather forecast. People do die in these every year, so you need to very cautious.
On cliff trails, beware of loose sand or pebbles, as these can become very slippery. Also, some travelers become distracted at cliff edge viewpoints if they are using cameras or binoculars. Drop dead gorgeous views should not be literal.
Never throw or roll rocks on from cliff edges, as you could start a rock fall and, more likely, there might be hikers below you whom you could hit.