What do you need to know to calculate the heat needed to melt a block of ice at its melting point?

To calculate the heat needed to melt a block of ice at its melting point, you need to know the mass of the ice block, the specific heat capacity of ice, and the heat of fusion of ice (or latent heat of fusion). The formula to calculate this heat is Q = m * ΔHf, where Q is the heat energy, m is the mass, and ΔHf is the heat of fusion.