warm up

run until the normal working temperature is reached; "We warmed up the car for a few minutes"

become more friendly or open; "She warmed up after we had lunch together"

get warm or warmer; "The soup warmed slowly on the stove"

cause to do preliminary exercises so as to stretch the muscles; "The coach warmed up the players before the game"

make one's body limber or suppler by stretching, as if to prepare for strenuous physical activity