  We analyze the prospects for stabilizing Majorana zero modes in semiconductor
nanowires that are proximity-coupled to higher-temperature superconductors. We
begin with the case of iron pnictides which, though they are s-wave
superconductors, are believed to have superconducting gaps that change sign. We
then consider the case of cuprate superconudctors. We show that a nanowire on a
step-like surface, especially in an orthorhombic material such as YBCO, can
support Majorana zero modes at an elevated temperature.
