The engine is hot, the heater core is not.
Coolant is not flowing through the heater core.
Toyota uses a flow valve to allow the coolant to flow through it.
The valve is probably stuck.
Follow the heater hoses until you find the valve and see if it's stuck.
Maybe even replace it, or back flush your heater core. Maybe it's plugged?
Or maybe the blend door in the heater box is stuck?
It could be a number of things.....