The beach of Evpatoria Bay is covered by a thick layer of sand that allows extensive use for natural sand baths (a powerful stimulant for nerve endings located in the skin). On Evpatorian beaches, natural, sun-heated sand baths are used with great success. The best time to take sand baths is in the dry summer months of July to August. Evpatoria's beaches are composed of quite large grains of sand (0.25 to 0.50 mm in diameter) with a wide variety in structure, which promotes the formation of air pockets. These air spaces lower the sand thermal conductivity. The amount of energy needed to heat one gram of sand by 1 Celsius is low. Because of this fact, the upper layer of Evpatoria's sand is wonderfully warmed by the sun's rays, to a depth of approximately 5 centimeters. On the Black Sea coast, in Evpatoria in particular, naturally heated sand baths have been used from ancient times for public medical treatment. Local residents and visitors from various locations came and treated their sick children with the coastal sand heated by the sun - and they quite often found total healing. The more or less methodical allocation of sand baths under medical supervision was established in Evpatoria as early as even 1909 to 1910. At that time, one by one, outpatient clinics, day sanitariums and beaches began to open.