Hot stimuli have analgesic effects and reduce muscle tone; BT increases the secretion of β-endorphin, corticotrophin, cortisol, growth hormone, prolactin and influences the serotonin and dopamine function helping to improve the characteristic symptoms and quality of life of FS patients (Cheleschi et al. 2021; Gálvez et al. 2024; Antonelli et al. 2024a, b). Here, GH1 is linked to Feingold syndrome.