The biological effect of the therapeutic infra-red spot-heaters used here results from the great depth at which they have their effect and the powerful heating effect on the organism. The resultant improvement in the circulation of the blood to the cells and organs enables the horse to eliminate metabolic slack from its system more quickly and to mobilise the antigens in its body.
Heat is absorbed by the horse and distributed throughout its body by its circulatory system. Because most of the radiation penetrates through the outer skin and germ layer without being absorbed, there is no possibility of local over-heating occurring and the thermal burden on the skin is minimal.