Answer :
Explanation:
When people get to higher attitude the amount of gas molecules in the air
becomes limited, since that happens it means that people will need more oxygen to have the blood flowing to be steady, so that's why people will carry portable oxygen tanks.
Bonus- "This makes it harder to breathe because you need to inhale"
Explanation:
This is because, without extra oxygen, climbing Mount Everest is a very big risk. Mount Everest is located where there can be extreme weather, steep and icy slopes, also deep colds that drop to -41℃. So it is a very good idea to bring extra oxygen.