is it true when a person sweats to cool the body sodium electrolytes and water are releases from the sweat glands in order to draw heat out of the blood circulating through surrounding tissues by evaporating water on the skins surface

Yes, that is correct. When a person sweats, the sweat glands release a combination of water, sodium, and electrolytes onto the skin's surface. The process of evaporating this sweat helps to draw heat out of the blood circulating through surrounding tissues, ultimately helping to cool the body down.