Fluid flow and heat transport phenomena of a liquid droplet colliding with a substrate are modeled. The fluid flow model accounts for the deformation of the droplet. The heat transfer model accounts for heat transfers within the droplet and the substrate. The mathematical models are numerically solved using a finite element method. Calculations are performed for the case where a molten tin droplet impacts various substrates. As a result, the following conclusions were obtained: 1) The periphery of the spreading droplet is more rapidly cooled than the central region. 2) The effects of initial temperatures and thermophysical properties of the droplet and the substrate on the temperature at the liquid-solid interface can be assessed using the analytical solution for the case where two infinite solids of different initial temperatures are contacted. 3) Heat transfer rate at the liquid-solid interface is dominated by the heat conduction within the substrate. 4) The heat transfer rate at the liquid-solid interface increases with increasing preimpact velocity of the droplet;. The increase of the heat transfer rate is due to enlargement of the heat transfer area rather than improvement of convectional heat transfer within the droplet.