The Frozen Tower

From the introduction: As the party steps through the portal from the rather warm and cosy library of House Lumbrox in Neverwinter city, they are instantly slammed with a frigid howling wind assaulting their senses. As their eyes refocus to the bright light, they realise they are on an open level high up above the ground. The wind howls through the eyrie chilling the players to the bone, players not dressed warmly or susceptible to the cold will begin to have their movement decreased and gain a disadvantage on any attack rolls.