Read it as minus 20 degrees.
From another source:
BENGALURU: The Light Combat Helicopter (LCH) recently completed the cold weather trials in Leh and team LCH says that the trials covered engine starts with internal batteries after overnight cold soak at 3km altitude and 4.1 km altitude. HAL chairman T Suvarna Raju said in an official communique that the engine starts were satisfactory in the temperature of minus 18 degree C at 4.1 km. "The flights were also carried out to assess high altitude performance and low speed handling," he said.