14 DAY TRIAL // You've probably heard than when a lightning storm catches you on open ground, you shouldn't take cover under a tree. That's true. Since lighting often strikes the highest spot in an area, ducking below a tall tree is definitely not a good idea, since you'll probably be struck in the same time.
If you're caught in an open area, with no places to take cover (a lonely wooden tool shed is not recommended) you are the tallest spot, so the chances of being struck increase. You shouldn't lie on the ground either!
The best solution is to crouch, in a fetal position, only vertical, and to stand on your toes, the idea being to minimize the contact area with the ground. You should also lose all metal objects, like watches, metal lighters, belt buckles and metallic jewelry.
This may not be the ideal situation to be in, since a lightning storm can last for some time, but at least it's a good temporary solution.
The ideal hiding place is a car. Any car in the world, except for the soft-top convertibles. Nothing will happen to you when lightning strikes the car with you inside. No, it's not the rubber tires that isolate the electric charge from the ground, it's just the fact that the body of the car has a wide surface, thus dissipating the electrical current and acting like a protective cage.
However, if you don't have a car, try to take cover long before lightning can form directly above you. A good way to calculate how close to you the last lightning was is the following thunder.
Since sound travels at 340 meters per second (1,115 feet) you should count the delay between the lightning and the thunder, in seconds, and multiply with the distance, to give you an estimate of the distance, in straight line.
So, a 5 second delay means that the lightning struck at 1.7 km (around 1 mile) which is not much. If the delay decreases rapidly and consecutively, then it's time you got the hack out of there, as fast as you can!