What happens when the salt is heated is the moisture attracting properties of the salt are activated, this allows natural humidity in the air to condense on the surface of the salt blocks, starting a natural ionization process. During this process, the salt blocks release negative ions that in turn attach themselves to dust and bacteria effectively purifying the circulating air. In addition to the benefits of the infrared sauna, the himalayan salt blocks release negatively charged ions as well as allow our bodies to reap health benefits including stress reduction, energy increases, and mood boosts.