Suppose one is in distress in the wilderness, and is being searched for by planes or helicopters because they thoughtfully told their friends where they were going and when they'd be back. Alternately, suppose you're just on a hike but happen to look very similar to a party of lost hikers.
How would you indicate to the crew of an aircraft that you are or are not in distress? Are there globally recognized hand signals to definitively say "I need help" or "I'm fine"? What if one wanted to relate more specific information, such as how many people are injured or what type of supplies you need?