Answer:
Some actions can have a negative impact on both your mental or physical health. Let's take the classic example of "If your friends are jumping off a bridge, will you do it too," for your physical health.
If you see your friends jumping off into the lake you may say "Wow! That looks fun," and do it immediately. When you reach the lake you realize there was a rock hidden under the surface of the water. You hit the rick and fracture your leg. If you had first thought "Is this safe," you could have avoided the injury.
As for your mental health, let's say your friend takes your phone to play games without asking and you had a personal text message open. If you react without thinking, you may shout at your friend and damage your friendship. Damaging a friendship is sure to have a negative impact on your mental health. Alternatively, if you take a breath and think before reacting to your friend, you may be able to take a much more effective light approach to the situation.