Why can't we take shelter under the big tree when it rains heavily?

When it rains heavily, you can't take shelter under the big tree because it may be struck by lightning or cause harm to human body. For people who stay under trees, lightning has three forms of damage:

1. When the human body is in contact with the tree, a strong lightning current flows through the trunk, generating high voltage to knock people down. This is because the human body is in direct contact with this high voltage, which is usually called contact voltage injury.

2. Secondly, although people are not in contact with trees, when lightning current flows through the trunk, the high voltage generated is enough to discharge the human body through the air, which is usually called counterattack injury.

People keep a certain distance from the tree even if they don't touch it directly. But standing under a big tree, when powerful lightning flows into the ground and spreads around, it will produce different voltages in different places, and there is a potential difference between the two feet of the human body, so there is current flowing through the human body, causing harm. It is often called step voltage injury. The discharge object of thunderstorm is selective, and the lightning current always chooses the shortest and most conductive path to discharge to the earth.

In an open place, trees and people are often the tallest, so they are often hit by lightning. Therefore, in thunderstorm weather, open fields, beaches, the sea and even football fields and golf courses are very dangerous places.

On a thunderstorm-prone day, first of all, try to avoid going to these empty places. When you see lightning in the suburbs, you immediately hear thunder, which means you are in a thunderstorm-like environment. Stop walking immediately and squat down immediately with your feet together. This will lower your effective height. But lying on the ground is not good either. Although the height is reduced, don't forget that there is still a step voltage. As mentioned above, when lightning current flows into the ground and spreads around, it will produce different voltages in different places. When lying on the ground, there will be a great potential difference between the head and the feet, so there will be current flowing through the human body, which will do harm to us.

If time permits, the biggest possibility is to squat in a nearby low-lying place or cave. Remember at this time that low houses and trees are not safe places.