If you considered players naked to heat - they can freeze in no time -, they should be "naked" to water too. In real life if you jumped out from a pool, you can run as fast as always. So if you are in the water, your wetness is 100%, but as you jump out, most of the water just runs down.
Water takes energy to evaporate and store it when the air humidity is high.
Here is an example: You swam around a bit in leather armor. You jump out, your wetness drops to around 15%. In the open air the water takes the energy and evaporates, heating up the leather is slowed down. But after water in the armor is gone, the leather will heat up faster and so you'll too.
Iron can't take water, so after a bath your wetness drops down below 5%, but clothes made of wool can be more soaked and makes you slow.

That can add a lining to resist cold and heat by combining with armor