A dispersion of an alkyd-containing polymer dispersed in water is used to form a waterborne coating composition; the alkyd-containing polymer being an acrylic-modified alkyd polymer, a silicone-acrylic-modified alkyd polymer, or a mixture thereof. The resulting waterborne coating composition includes about 2 to about 30 % by weight of one or more thermal insulating fillers with the remainder beingthe alkyd-containing dispersion, such that the coating composition contains about 30 to about 80% by weight of the water and about 2 to about 50% by weight of the alkyd-containing polymer. The coating applied therefrom exhibits at least one of the following properties: a thermal conductivity that is less than 100 mW/mK; a weight retention of at least 70% after being heated up to 400C as measuredby thermogravimetric analysis (TGA) with a heating rate of 20C/min.; or a weight loss of less than 50% up to a temperature of 470C as measured by the TGA.