I have heard this many times, however, it has not been my experience based on various large game animals taken at sub zero temps. Largest was a large bull moose taken at minus 26 actual temp. No idea what he wind chill was (15 to 20 MPH wind) but the skinned quarters froze solid very quickly. The hindquarters were band sawed two days after the moose was killed and center was fully frozen with no souring.