How to avoid empty temp schemas

After some time of working, Postgres 8.1.3 on W2K creates large a number of
empty schemas in my database.

Those schemas are named  pg_temp_1 .. pg_temp_13  (some names are missing in
sequence).

Some of them do not contain any objects. Some contain temp tables created by
my application.

Is it safe to remove those schemas ?

How to force Postgres to remove empty schemas automatically ?

Andrus.