This paper presents a blood-perfused skin model as implemented in a spreadsheet software application for accessing burn injuries resulting from exposure of skin surface to flowing hot fluids or constant heat sources. Finite-difference analysis of heat transfer in skin burns provides an accurate prediction of tissue time–temperature relationships throughout the duration of thermal insult. The Henriques theory of skin burns is used for determining the spatial and temporal extent of tissue damage. The epidermis, dermis, and subcutaneous fat were modeled as uniform elements with distinct thermal properties. Method for implementing finite-difference solution in spreadsheet software has been described. A comparison of the injury threshold computed by this model against Henriques's result has been done and the results are in good agreement.