An important construct that has long been associated with feelings of social connectedness, interpersonal closeness, and security is warmth. In everyday language, phrases such as "warm embrace" are often utilized in situations where social connections are of interest, and words of similar nature are also used to describe personality traits. Although a growing body of empirical research has consistently demonstrated that physical warmth is closely linked to social intimacy and proximity, extant research has not examined whether the presence of romantic partners is similarly associated with physical warmth. The studies presented in this dissertation were the first ones to investigate the link between romantic partner presence and perception of physical warmth and reveal that imagining romantic partner presence or absence altered thermal perceptions. Across five studies, it was consistently found that simply imagining being together with the partner was associated with feelings of warmth, whereas imagining being separated from the partner was associated with feelings of coldness. Moreover, thinking about partner absence (vs. partner presence or a control scenario) was associated with a greater desire for warm activities potentially to compensate for the feelings of coldness. Together, these findings extend the consistent findings on the link between social and physical warmth to romantic relationships and provide further evidence for the regulatory role of romantic relationships and the robust link between physical warmth and interpersonal affection.