To change ice at -64.0°C to steam at 52°C, you need to consider three separate phase changes: heating the ice from -64.0°C to 0°C, melting the ice at 0°C to water at 0°C, heating the water from 0°C to 100°C, vaporizing the water at 100°C to steam at 100°C, and then heating the steam from 100°C to 52°C. You would use the specific heat capacities and heat of fusion and vaporization for each of these phase changes to calculate the total heat required.