ɐkˈoːɹdɪŋ tʊ ˈeɪntʃənt ɡɹˈiːk fɪzˈɪʃənz, vˈaɪɾəl hˈiːt wʌz pɹədˈuːst baɪ ðə hˈɑːɹt, meɪntˈeɪnd baɪ ðə nˈuːmə ˈɛɹ, bɹˈɛθ, spˈɪɹɪt ɔːɹ sˈoʊl, ænd sˈɜːkjʊlˌeɪɾᵻd θɹuːˈaʊt ðə bˈɑːdi baɪ blˈʌd vˈɛsəlz, wˌɪtʃ wɜː θˈɔːt təbi ɪntˈækt tˈuːbz jˈuːzɪŋ blˈʌd tə tɹænsmˈɪt hˈiːt.
According to Ancient Greek physicians, vital heat was produced by the heart, maintained by the pneuma (air, breath, spirit or soul), and circulated throughout the body by blood vessels, which were thought to be intact tubes using blood to transmit heat.