An experiment is in the works at Fermilab to confirm that ionization cooling is an efficient way to shrink the size of a muon beam. This would pave the way for Muon Collider machines, which however require in their last stages of acceleration very high field solenoids. The use of high temperature superconducting materials (HTS) is being considered for these magnets using Helium or higher temperature refrigeration. A sample holder was designed to perform critical current (Ic) measurements of HTS conductors under externally applied magnetic fields varying from zero to 90 degree with respect to the c-axis. This was performed in an ample range of temperatures and magnetic field values. A description of the test setup and results for (Bi,Pb)2Sr2Ca2Cu3Ox (BSCCO-2223) tapes, and Second Generation HTS in the form of 348 superconductor are presented.