Comfort

The Sims
If a Sim has been standing up for too long, his or her Comfort meter will drop. Though it is not as important as the Hunger meter, Sims who become uncomfortable will become grumpy and irritable. Sitting down and relaxing is a quick and easy way of replenishing the Comfort meter, as is going to bed. Taking baths and hot tubbing will also improve your Comfort. Even if you're reading, watching television or playing the piano, your comfort level will rise as long as you are sitting down. Of course, different chairs, beds and baths will increase the Comfort level at different rates; for example, the Werkbunnst All Purpose Chair isn’t about to raise Comfort levels any time soon.

In places such as Downtown and Old Town, there are benches for your Sims to sit down and relax, but they aren't exactly comfortable. However, in Studio Town, there are massage tables and steam baths, which are comfortable.

The Sims 2
In Sims 2, comfort can be lost the same way energy is, by running and working out especially. A good way to get comfort back is to sleep on a more comfy bed and to relax in a hottub or have bath instead of a shower.

The Sims 3
There is no comfort in The Sims 3. Instead, working out and furniture affect Sims through moodlets.

Buy mode
Comfort is also a section in the Buy mode catalog. It contains dining chairs, living chairs, sofas, and beds--basically, items that affect a Sim's comfort motive.