Lava stones are valued because they keep warmth particularly well. It is thought that the the accumulated fire energy transfers to human body; the warmth penetrates to the muscles activating the vital functions of organism. The capillary blood pressure increases improving the blood circulation, the cell oxygenation improves, the metabolism speeds up. It is also claimed that lava eliminates joint stiffness, reduces joint and muscle pain, affects airway positively, increases resistance to the colds.