Air Conditioning on 2004 Ford Escape

why does the air conditioning quit blowing cold air at higher speeds, i.e. >60 mph

Asked by for the 2004 Ford Escape
Does the fan continue to blow air out the vents? But the air is warm?
yes the fan continues to blow, actually it is a gradual warming. city driving, air is good, get on the highway and gradually the air will get warmer