Icy water is a hazard in the Banjo-Kazooie series. Due to its low temperature, Banjo and Kazooie either recieve damage upon touching it or run out of oxygen twice as fast as normal while swimming in it.
In Banjo-Kazooie, icy water can be found in Freezeezy Peak and in the winter season of Click Clock Wood. While the former cannot be touched normally, only as Walrus Banjo or wearing Wading Boots as it deals damage to Banjo and Kazooie even if they use the Wonderwing, the duo can swim in the latter but run out of oxygen twice as fast.
In Banjo Tooie, icy water is found in the Icy Side of Hailfire Peaks. While the water found in the lakes and in Chilly Willy's arena work like they did in the Freezeezy Peak world of Banjo-Kazooie, the pool in the Icy Side's Train Station works like it did in the Click Clock Wood world of the same game, during winter.