Calorimetric measurements and optical observations have been performed to investigate the effect of chirality on a bent-core nematic (BCN) material which can exhibit an amorphous blue phase (BPIII) over a wide temperature range by mixing with a highly chiral dopant. It was found that the first-order character of the nematic (N)-isotropic (I) phase transition of the host BCN sample was clearly weakened by increasing the chiral dopant concentration and eventually moved into the supercritical evolution. The colors of the textures also showed a blue shift when increasing the chiral concentration.