Nature has a way of telling us when we're in danger, but it only works if we know the language. The more knowledge you're armed with about nature's warning signs, the safer you'll be hiking, camping, and really doing any extended activity outside.
In moments of anxiety, it's helpful to have a cursory knowledge of why different feelings are hitting your gut, so arming yourself with basic facts about the weather and behavior of animals can be an asset. Particularly, since you can't communicate with animals or the sky with the same fluency you could another human (and if you can, I salute you).
Hopefully, these are illuminating, but you don't have to use them.
If the animals get the f**k out, you should too.
If you are swimming at the beach or a coastal inlet and see an unusually calm area of water, get away from it, it could be a riptide. On that note. If you get stuck in a rip, don't swim against it, you will tire and drown, swim parallel to the coast till you swim out of the rip.