We discuss the high-temperature electronic and thermal properties of an icosahedral quasicrystal within the framework of the fractional multicomponent Fermi-surface model. When intervalley electron–phonon scattering sets in above a characteristic temperature T∗ of the order of the Debye temperature ΘD the quasicrystal becomes more “metallic”. In this regime the electrical conductivity and the electronic contribution to the thermal conductivity vary as T and T2, respectively. We predict that at elevated temperatures the electronic specific heat will vary faster than γT and the low-frequency Drude-type component of the optical conductivity σ1(ω) will gain weight.