Whistles with peas were abandoned by hockey leagues years ago (especially unheated or outdoor facilities). That is one sport where they DID freeze up. It is not a myth. The amount of times they blow the whistle or even hold the whistle up to blow leads to a lot of spittle in the whistle which can freeze and block the operation or at the very least atune the frequency so that it becomes a garble instead of a tweeeet.