Vaccines. Everyone breathes and coughs on everybody. Stay up to date on routine vaccines, including flu and Covid-19.

Stampedes, or crowd crush. The CDC (U.S. Centers for Disease Control and Prevention) recommends: Keep your hand in front of your chest like a boxer and keep firm footing. Don’t resist the force of the crowd. When there is a lull in movement, work your way diagonally to the edge of the crowd. Try to stay on your feet. If you fall, protect yourself by curling into a ball. Stay calm and get up as soon as you can.

Heat illness. Standing in the sun all day can burn your skin and dehydrate you. Cover up (hat with a brim, long sleeves), wear sunscreen, and drink adequate non-alcoholic fluids.

Security. Pickpockets abound. For openers, don’t put valuables (wallet, passport) in your pants pocket. Instead put your valuables under your clothing in a money belt, or a hotel safe.

Before traveling to a foreign country, check out the CDC site Travelers’ Health for info regarding staying fit. This site lists recommendations, including vaccines and malaria prevention, for every country in the world.

Take a look at the U.S. Dept. of State Travel Advisories site, which posts a statement on security concerns for every nation.

Register for the U.S. Department of State’s Smart Traveler Enrollment Program (STEP), which provides travelers with relevant notifications, including travel warnings and other destination-specific info. STEP also allows the State Department to locate you if you have serious legal, medical, or financial difficulties while overseas, and can aid friends and families in locating you.

References
CDC: Travel to Mass Gatherings
CDC: Mass Gatherings
U.S. Dept. of State STEP