This is a highly specific, life-saving Lal Kitab warning from Dr. Sharma.
The 5th house is the house of children, emotions, and the Sun (mountains/heights). The Moon (Chandra) represents water, emotions, and peace.
When the Moon sits in the 5th house, traveling to high altitudes or mountainous regions clashes with the planetary energies. Dr. Sharma warns that if this person frequently travels to the mountains ("pahadon ki yatra"), it will trigger severe emotional trauma, depression, or tragedies in their life, causing a literal "waterfall of sorrows" ("dukhon ka jharna"). Stay near the plains or water bodies instead.