It really does depend on the person. I was in Cuzco as a teenager many moons ago, sat quietly sipping my cocoa tea and doing nothing for the first few hours. I got up to take a short walk with my dad, fainted, was taken to the hospital and on oxygen for the next 12 hour. I has some pretty bad bruises on my face from the fall which healed I n credibly fast in the altitude. My sister a year younger had no issues and continued smoking cigarette in the thin air where matches barely stayed lit.

Tibet many years later..I was very careful and did nothing the first half day. That night we went to a restaurant with tradititonal folk dancing and for some unknown rea s on or calling, I joined in the Dancing. I was fine. Climbed the Potala the next day.

A little insomnia, feeling full on very little food were the only effects in Lhasa or on the trip to Lake Namtso where we crossed a path even higher than LH as a.

I know some like to take preventative meds but I like my body to react first so I know what I'm dealing with. Listen to your body.

PS my family were skiers and every time we went to Colorado I fainted several times, in the ski lift line, lunch line, carrying my skis up to our condo. Maybe I grew out of it as I got older. Don't know, but it didn't stop me from exploring