The sensation of a warm hug does far more than provide comfort — it fundamentally confirms a person’s physical existence to their brain, according to research that identifies temperature as a critical component of human identity.
A new review published in Trends in Cognitive Sciences challenges the traditional view of body temperature as a purely physiological signal. Instead, researchers argue that “thermoception” — the perception of thermal changes — is a primary “skin-to-brain” pathway that defines where the body ends and the rest of the world begins.
“Temperature is one of our most ancient senses,” says Dr Laura Crucianelli, Lecturer in Psychology at Queen Mary University of London. “Warmth is one of the earliest signals of protection… It keeps us alive, but it also helps us feel like ourselves. By studying how the brain interprets warmth and cold, we can begin to understand how the body shapes the mind.”
Detachment from the self
The findings offer potential breakthroughs for treating conditions characterised by a detachment from the self, such as anorexia nervosa, depression, and trauma-related disorders.
“For example, we now know from experimental studies that thermal signals play a fundamental role in clinical conditions,” says Professor Gerardo Salvato of the University of Pavia. “People with altered temperature regulation and temperature perception, due to a brain stroke, may develop pathological conditions according to which they do not recognise part of their bodies as belonging to themselves.”
The researchers identified the specific biological mechanism that makes a hug feel “grounding.” Warm interpersonal contact engages C-tactile afferents and thermosensitive pathways that project to the insular cortex — the brain region involved in processing emotions and bodily awareness.
This sensory input triggers oxytocin release and reduces physiological stress.
“When we hug, the combination of tactile and thermal signals increases our sense of body ownership, so we are more connected to our embodied sense of self,” says Dr Crucianelli. “We feel, ‘this is my body, and I am grounded in it.’”
Beyond clinical therapy, the research suggests that integrating realistic thermal feedback into prosthetics could help users accept artificial limbs as natural parts of their bodies.
The authors also warn that rising global temperatures could impact mental wellbeing in unexpected ways.
“As global temperatures rise, understanding how warmth and cold shape the relationship with ourselves may help explain shifts in mood, stress, and bodily awareness in everyday life,” the authors note.
