"applications must take care not to overflow the exponent"

[Bruce M. Axtens]

G'day everyone.

The manual says, "mpf functions and variables have no special notion of 
infinity or not-a-number, and applications must take care not to 
overflow the exponent or results will be unpredictable. This might 
change in a future release."

 From a reactive point of view, how does one tell if one has overflowed 
the exponent? Or, from the proactive, how can one tell if exponent 
overflow is likely?

Kind regards,
Bruce.