You can also buy stuff to insulate the hoses. The cheapest material is often another hose.... Otherwise there are various materials made for high temperature.
In terms of getting them to work correctly, as I understand it, even hooked up backwards the heater is going to work fine.
Heres a snippet from a FSM on how the heater hoses show flow for the 2rz/3rz:
http://www.2rzturbo.net/wp-content/uploads/2014/10/2rz_cooling_path.jpg
