The heat loss from the Dundas Island polynya is calculated for a 3 week period during March 1980. Bulk and free convection formulae based on sonic anemometer-thermometer measurements are used to calculate the sensible and latent heat fluxes. These terms, along with simple models to calculate the albedo and the long-wave radiation exchanges, yield a surface heat budget for the polynya. The sensible heat flux for the period March 12, 1980, to April 1, 1980, averaged 204 W/m2 and the mean total heat loss from the polynya was 329 W/m2.