AbstractWe propose a method for calculating nonstationary heat fluxes using the electric-response signal of a sensor based on anisotropic bismuth single-crystal thermoelements. Using this method, it is possible to approximately calculate the heat flux during a period of time from ∼1 μs to the attainment of a stationary thermal regime. Tests showed that the monitoring of short-term ( t ∼ 1–10 ms) heat fluxes by bismuth-crystal-based sensors with a crystal length to thickness ratio of above 25 ensures a calculation error not exceeding several percent.