Minor nitpick: it's not true that "a body will emit exactly as much as it absorbs" in general. That's only true once it reaches some equilibrium temperature, wh

Minor nitpick: it's not true that "a body will emit exactly as much as it absorbs" in general. That's only true once it reaches some equilibrium temperature, which may not be room temperature. If you stick a room-temperature metal sheet outside on a sunny day, it will heat up until it reaches a steady state where the rate of heat absorption is equal to the rate of heat dissipation -- this can be significantly higher than room temperature, which is why pieces of metal outside on a hot day are really really hot.