The authors hypothesized that people's predictions of how other people feel in emotionally arousing situations are often based on people's predictions of how they themselves would feel in those situations. Indeed, most participants in Study 1 reported predicting hungry hikers' feelings by mentally trading places with them, imagining what their own feelings would be in the hikers' situation. Because people's predictions of their own feelings tend to be biased in the direction of their current drive states, we hypothesized that mentally trading places would lead to social projection of transient drive states. In Study 2, participants' predictions of whether thirst or hunger would be more bothersome to hikers lost without food or water were biased in the direction of participants' own exercise-induced thirst. Furthermore, participants' predictions of how they would feel in the hikers' situation statistically mediated the effect of exercise on their predictions of the hikers' feelings.