Passage: The MiG-25 underwent substantial design sacrifices in order to achieve high speed, altitude and rate of climb. However, it lacked maneuverability at interception speeds and was difficult to fly at low altitudes. The MiG-25's speed was limited to Mach 2.83, but it could reach a maximum speed of Mach 3.2 or more with the risk of engine damage.

Question: What type of altitudes did the MiG-25 have difficulties flying at?
low altitudes