Ultrafast heating of cold holes is investigated in bulk GaAs using a high-sensitivity two-color absorption saturation technique. Measurements performed as a function of the lattice temperature and of the carrier excess energy show that absorption of optical phonons is the main hole heating mechanism for the investigated temperatures in the range 100–300 K. Using a numerical model for carrier dynamics, the optical deformation potential is estimated to bed0∼40 eV.©1997 American Institute of Physics.