I once stunned a nerve that runs alongside my thigh icing for some hip soreness. My entire upper leg was numb/tingling for about two and a half weeks. Perhaps you just stunned a nerve in your legs, which my trainer says can happen from ice, heat, or pressure, particularly if you are very thin like me. When sitting change positions often so you don't screw it up more. Obviously, if it persists for more than three weeks, spreads/intensifies, or you begin feel weakness then you better see a doctor.