Results of an experiment performed at drifting ice station FRAM I in the Arctic Ocean northwest of Spitzbergen during March--May 1979 indicate that sensible heat flux from the ocean to the ice cover was less than 2 W m2. The estimate is based on measurements of temperature gradient, growth rate and salinity of young sea ice. Uncertainty in the magnitude of the heat flux results more from evidence of horizontal inhomogeneity in the growing ice sheet than from measurement errors.