Temperature of the main unit
The VIDEO4 main unit dissipates about 5W of power. The VIDEO4 sport uses a very small fan to aid in temperature regulation, whereas the metal body of the VIDEO4 professional acts as a heatsink and is passively cooled.
In both cases the units must be placed away from any sources of heating (engine, exhaust etc) and surrounded by free air.
Both units have a maximum internal temperate of 70oC and above this temperature will power down into a very low power state. Once the unit has cooled down the unit will power up again as normal.
Note that for sport units fitted with the internal battery operation that it is even more important to not expose the batteries to excessive temperature. If the batteries are exposed to temperatures higher than 60C then there is a risk that the batteries will leak and fail causing internal damage that is not covered by the manufacturers warrantee.