The reactions that take place during cooking happen more slowly at lower temperature, therefore if you cook at altitude in boiling water at 92°C, it will take longer than at sea level in boiling water at 100°C. It is temperature, not the physical act of boiling, that cooks food. (That is the point of a pressure cooker - by applying high pressure, the boiling point of water increases, so cooking occurs at higher temperature and thus is faster.)