How do you tell if an H2O pump is failing? (NAC)

[l.leung at juno.com]

I was driving my beater (keeping the
200Q a virtual hanger ('er cover) queen,
last night and this morn and 4 events
occurred:

1) Heater suddenly blew COLD.
2) Temp guage climbed.
3) Overflow bottle NEARLY bubbled over.
4) Radiator stone cold.

Car, '90 Scooby Legacy, ambient temps
around 35 last night, 12 this morn (degrees
F). Is this the water pump?

TIA!

LL - NY