The present paper describes paraffin/polyethylene-based composites modified with functionalized carbon nanotubes with the ratio 'length: diameter" of "10:1..100:1". These composites possess electrical conductivity and are capable of generating heat under direct current supply conditions. The experiments performed showed that under the action of electric current, the composites are heated up to the stable temperature of 48.3 °C. The effect of maintaining such a temperature is associated with the availability of paraffin in the material composition. © The Authors, published by EDP Sciences, 2018.