All Toyota hybrids use some sort of heat recovery system - the 1st/2nd gen Prius uses a Rube Goldberg-esque system of a coolant thermos(think a big Hydro Flask/Yeti bottle), a three-way valve controlled by a stepper motor, a pump and a mess of hoses. The PCM will command the coolant heat storage system to dump warm coolant to pre-temp the engine during start and run the system in bypass mode while the car is moving. When the car is shut down, the CHS pumps hot coolant into the thermos and commands the 3-way valve to shut off the tank.
The 3rd gen Prius and all recent Toyota hybrids uses a exhaust heat recovery system - the cats are plumbed to the cooling system. Now that cats are being stolen off those, the risk of inflicting severe engine damage via overheating if you drive around decatted is real.