Lama Ole’s answer:
If strange energies come to you, there are two possibilities: either you have a negative connection to them from before and they want to harm you, or you owe them something and they’ve come to you for help. In both cases, compassion is the best solution. Before the meditation, you wish all the best for all beings. From your heart you radiate out rainbow light in all directions, wishing that it dissolves the suffering of all beings. Then you begin with the actual meditation, and there will be no problem.
Or you can take the help of the Buddhist protectors. The most important thing with the protectors is that we don’t use their mantras right away when there is a problem. Instead, we invoke the protectors in our daily practice to make ourselves strong. Then when the disturbing energies come, we can be gentle. It’s like with dogs: only the small ones need to bark. People with no protection and no power will start out aggressively, while those who are strong are also even tempered. The strong ones watch what happens but the disturbances don’t come—their energy field is not disturbed.
That said, there are also difficult places where it is simply unpleasant for everybody. The most difficult are slaughterhouses, where many animals have died.