The entire temperature gradient in an ice sheet can be shifted by processes that occur just below the surface. Energy absorbed close to the surface flows back to the surface which steepens the average temperature gradient near the surface and shifts the entire temperature profile to higher values. For a constant density this shift equals Aˆ/α2k, where Aˆ is the average annual strength of the energy source, α is its exponential decay rate with depth, and k is the thermal conductivity. Various sources are considered as are density profiles and transients. While some sources can increase the 10-m temperature in ice sheets, air currents flowing through snow can either heat or cool the snow at depth and can dominate all other processes. The relative contributions of the different mechanisms must be evaluated for any particular site.