This article was originally published in Psychology Today.

I went to dinner recently with a group of old friends with whom I’d fallen out of touch. After the usual catching up on what we’d missed in the intervening years, we fell quickly into an evening of “nostalgizing.” We shared fond memories, and I went home that night feeling warm, happy, and loved. According to science, I experienced exactly what nostalgia does to us—and why it’s good.

To nostalgize is to revel in nostalgia, “a feeling of pleasure and also slight sadness when you think about things that happened in the past.”[i] A 2011 study[ii] published in the Journal of Personality and Social Psychology found that participants who were induced to feel nostalgic by listening to a favorite hit song from their past “were more likely than a control group to say that they felt ‘loved’ and that ‘life is worth living.’”[iii] According to the appropriately titled “Heartwarming memories,”[iv] published in the journal Emotion,colder days trigger more nostalgia than warmer ones, and “participants who recalled a nostalgic (vs. ordinary autobiographical) event perceived ambient temperature as higher.” In other words, warm memories can make you feel warmer, literally.