IR has a very broad range, including heat. Water is used to absorb this IR radiation.
"IR" in photography is only a very narrow range directly below the visible range. Except from the fact that we (and as a consequence to this all normal colour films) cannot see this radiation it behaves more or less the same as visible light.
Snow flakes have a very fine structure which scatters back light. This is basically the same effect as the wood effect. Chlorophyll is transparent to IR and the foilage structure scatters back the IR light which makes it look "white". Chlorophyll is missing in snow which is the reason why it looks white in the visible range as well.