An igloo is an object which Sims can use to sleep inside. Igloos are usually associated with winter and snow. Igloos were first introduced in The Sims: Vacation, and later made an appearance in The Sims 3: Seasons.
The Sims: VacationEdit
Igloos are one of the lodging options available on Vacation Island. In the default lots, igloos will be found in the snowy area.
Igloos rent for 79 simoleons a night, and two Sims can sleep in one. When Sims who are sleeping in an igloo wake up, they automatically change into the appropriate clothing for the area of Vacation Island they're in. Just having a hotel key doesn't allow Sims to use igloos, but Sims that have hotel keys can rent them. While the rental shack clerk talks of "checking out" when an igloo is rented, what appears to happen is that the rental expires at 11:00 AM.
The Sims 3: SeasonsEdit
Igloos returned in The Sims 3: Seasons. During the winter, if the snow is deep enough, Sims can build igloos. They can ask other Sims to help them and they can build them on any flat space, even on community locations. When they are finished being built, igloos are treated like beds, so Sims can go inside and relax in them, play in them, sleep in them or even WooHoo in them, or perform a series of other social interactions if another Sim is in the igloo with them. When it gets warmer, igloos will melt. It will look caved in, and Sims can no longer interact with them. Like snowmen, igloos can be picked up in Buy mode, moved around and sold.