This is a similar mechanism, but within the endorphin pathway. So what does it mean? It means that a little bit of discomfort as a consequence of deliberate heat exposure, while in the short term, doesn't feel good, by definition, it is activating pathways that are allowing the feel molecules and neural circuitries that exist in your brain and body to increase their efficiency, placing you in a better position to be joyful in response to the events of life.