Abstract
A graphical representation of heat transfer measurements and a graphical solution of the heat transfer equation, describing the temperature changes in a fluid flowing in a pipe localised in a heated or cooled region, are given. The solution is applicable to the axial temperature distribution of the blood in a vessel passing a region of higher or lower temperature. An experimental study of the temperature distribution in small pipes with various flow rates and pipe diameters is presented. The results add information on convective heat distribution in vessels to available knowledge of conductive heat distribution in tissues. The results can be used for the analysis of temperature changes in the vicinity of pathological processes accompanied by vascular changes, e.g. primary venous or arterial disease, inflammatory conditions or neoplasia.