"Wind chill" is just a sensation that results from the wind taking heat away from your (nominally 98.6 degree) body more quickly than you would lose heat in the absense of wind. It will not cool you to a temperature lower than the actual temperature of the air. In particular, water will not freeze at a higher temperature just because it is windy, so "49 degrees with 10 degrees windchill" is no closer to freezing than regular 49 degress.