Final answer:
After inadvertently entering a thunderstorm, it is important to take safety precautions such as seeking shelter in a sturdy building or a hard-topped vehicle, avoiding tall objects and open fields, and waiting for at least 30 minutes after the last sound of thunder before resuming outdoor activities.
Step-by-step explanation:
After inadvertently penetrating a thunderstorm, it is important to take certain actions for safety. Firstly, if you are in a car, it is advisable to stay inside as the metal body acts as a Faraday cage, protecting you from electrical fields. If you are outside, seek shelter in a sturdy building or a hard-topped vehicle. Avoid tall objects and open fields. If you cannot find shelter, crouch down low with your feet together, avoid water, and stay away from metal objects. It is recommended to wait at least 30 minutes after the last sound of thunder before resuming outdoor activities.