What do populations living at high elevations have to adapt to?

Question

Lower oxygen levels.
Lower ultraviolet, light intensity.
Higher heart rates among children.
Higher average temperatures.

Answer 1

Increased risk of altitude sickness.
Thinner air, which can affect breathing and physical performance.
Increased exposure to intense sunlight due to thinner atmosphere.
Limited access to healthcare facilities.
Limited availability of certain agricultural crops and food supplies.
Adaptation to colder temperatures due to higher elevations.