If you're from a really cold climate then maybe you could do it and not freeze,I'm not doing it, even the warmest days in January are not doable for someone used to warmer temps.I've done two visits to water parks that the temperatures were just way too cold to be at a waterpark for me,once the low was in the upper 50s and the high was in the 74-78 range,I was freezing most of the time,the exception was if I was in the sun for an extended time,anywhere with shade I was turning blue.The other one I believe the high was in the 80-82 range and it was not as bad as the other visit but still far from ideal.If you're from somewhere really cold you would likely be fine.