  We discuss the interconnection between the Schwinger pair creation in
electric field, Hawking radiation and particle creation in the Unruh effect.
All three processes can be described in terms of the entropy and temperature.
These thermodynamic like processes can be combined. We consider the combined
process of creation of charged and electrically neutral particles in the
electric field, which combine the Schwinger and Unruh effects. We also consider
the creation of the charged black and white holes in electric field, which
combines the Schwinger effect and the black hole entropy. The combined
processes obey the sum rules for the entropy and for the inverse temperature.
Some contributions to the entropy and to the temperature are negative, which
reflects the quantum entanglement between the created objects.
