[en] Statistical electron parameter correlations associated with high-speed streams are determined with the aim of identifying one or more locally active solar wind heat flux instabilities. Strong evidence is found that the whistler mode is active in regulating the heat flux at 1 AU when (T/sub parallel//T/sub perpendicular/)/subH/approximately-less-than1.2 and N/subH//N/subp/approximately-less-than0.1