Because they find themselves in environments of little or no oxygen, and oxygen is essential to life.
Under ordinary conditions oxygen is itself a gas so cannot be said to carry a gas.
There is no free oxygen in space, so they need to carry oxygen with them to allow their fuel to burn and, in the case of manned spacecraft, for the crew to breathe.
Because your cells need oxygen. Blood has Hemoglobins inside it, which carry oxygen.
The red blood cells carry the oxygen in blood.
Oxygen is an element and it is not easy to make elements artificially.You can make artificial oxygen carriers that carry oxygen in the blood instead of hemoglobin.
It is because at high altitudes the oxygen is not sufficient..........
They have to carry oxygen cylinders with them as it allows them to breath at high altitude. The temperature also decreases as we go higher and higher.
Because at great heights ie up mountains the air becomes 'thinner' this means there is less oxygen and so it is harder to breathe. So they carry the oxygen so that they can continue up the mountain otherwise they will be unable to coninue because it is dangerous.
A climber carries an oxygen cylinder on their back because it helps him/her to breathe easier. On high altitude mountains like Mount Everest the air is so thin it makes it very hard for anyone to breathe without extra oxygen from a cylinder.
At extreme altitudes, the air becomes rarefied and has a very low oxygen concentration. This can lead to a condition known as hypoxia, which is deprivation of oxygen to the brain, which can cause loss of consciousness, paralysis, and death.
because the higher you go up a mountains are the less oxygen there is.
Mountaineers condition themselves by expanding their lungs. They carry oxygen on climbs to altitudes where it will be needed.
The higher you go up away from the Earth's surface, the less oxygen can be found in the air and more of gases we don't need to breathe in. So, as the mountaineer goes higher up, breathing becomes harder and your body works slowly, reducing reaction times. By carrying an oxygen tank, the mountaineer can always be breathing the perfect concentration of oxygen they need at all times.
Mountaineers carry oxygen cylinders with them on high altitude mountains like Mount Everest. This is because the higher the mountaineer climbs the less air there is to breathe.When you travel in an aeroplane at a high altitude the plane will be pressurized. A cabin air pressure at cruising altitude is lower than air pressure at sea level. At typical cruising altitudes in the range 11 000-12 200 m (36 000-40 000 feet), air pressure in the cabin is equivalent to the outside air pressure at 1800-2400 m (6000-8000 feet) above sea level.
Climbers need to wear oxygen masks to help them breathe as the air is thin higher up Mount Everest than at sea level.
Ambulances carry oxygen cylinders because it is often used to revive people, e.g. For people rescued from drowning or people rescued from smoke filled rooms.Hospitals also use it for patients with breathing difficulties e.g. asthma.
If you mean 'Why do climbers carry oxygen cylinders on mountains' then that is to survive. On high mountains like Mount Everest the air (oxygen) is so thin you need help to breathe, so they use oxygen from a cylinder.