First objective is always to find cover, even if it's the edge of the sidewalk. If cover is not within short distance then I usually listen to whether or not the shots are coming from close by or far away. If far away I either chance sprinting away or proning - depending on my direct areal surroundings. If close, I automatically turn while fully standing and start strafing as fast as possible while burst firing; with a hopeful option of finding cover.