heat exchanger may be dirty on the OUTSUDE - doesn't take much mouse nest trees fuzz and pine needles to clog 'er up. Also water pump impellers are toast after 100K.
Grab live data and see the actual water temperature measured by the engine computer.
I don't know if Toyota has a valve in the inlet water hose (Hondas do) and see if that is all the way to the open position. If it is there, it will be near the firewall.