Physical Danger
Lions, tigers, and bears, oh my: these are just three of the thousands of dangers that you may face in your days as an adventure travel leader. After all, the first word is adventure―even a casual hike up a tourist-filled mountain can feature bee stings, snake bites, spills, falls, sprained ankles, forest fires, thunderstorms, and perhaps a cougar or two (if they're not lazing about somewhere).
And you're not only concerned about yourself: you've got the entire Johnson family to worry about. No one except little Timmy has got a clue what they're doing.
That's why planning is such an important skill to have. You need to be aware of every second of every day and every mile of every journey (so, basically, everything about the trip). Weather, seasonal conditions, tides, and even human events need to be considered when taking a group of strangers into the wild blue yonder.
Second to planning is the ability to adapt when a plan totally falls through. Mother Nature is a fickle lady, and she does what she wants. Know your capabilities, know your plans, know your limits, and everyone should get home safe, sound, and completely intact.