We study the behavior of shell effects, like pairing correlations and shape
deformations, with the excitation energy in atomic nuclei. The analysis is
carried out with the finite temperature Hartree-Fock-Bogoliubov method and
a finite range density dependent force. For the first time, properties ass
ociated with the octupole and hexadecupole deformation and with the superde
formation as a function of the excitation energy are studied. Calculations
for the well quadrupole deformed Er-164 and Dy-162, superdeformed Dy-152, o
ctupole deformed Ra-224, and spherical Sn-118 nuclei are shown. We find in
particular, the level density of superdeformed states to be 4 orders of mag
nitude smaller than for normal deformed ones.