above 2500m
Mosquitoes are common in the tropics.
5432 mts source (www.aagama.com)
Mountains in the Tropics are covered in snow because of lapse rate. The lapse rate is for every 1,000 feet in altitude you travel up a mountain, the temperature drops 31/2 degrees F.
A Boeing 767 has an altitude limit of about 41,000 feet.
Generally, deserts located furthest from the tropics are cold deserts. The closer to the tropics, the warmer the desert. Some are considered cold because they are at a higher altitude and others considered as cool desert because they are on a coastline that has cold ocean currents just off shore
Variations in the altitude of the snow line are caused by the relative location of the nearest coastline and the latitude. At the Equator the snow line is at 4500 m and at the Tropics of Cancer and Capricorn can be as high as 5700 m.
The Gulf Stream carries warm water from the tropics, it might come near Scotland.
The higher the altitude the lower is the temperature so much so that fallen snow will not melt even in summer.
I have no idea, but I would assume so since the oxygen level decreases with altitude.
The safest value available. 0 if on the ground, the upper limit of survival in an aircraft, balloon etc...
As altitude increases so air pressure reduces, until the limit of our atmosphere is reached. After which the vacuum of space is entered.
3. It depends upon the position (Latitude, Longitude and Hemisperical Presence) and also altitude.