losing cold in fridge and freezer possible frost in freezer

Thanks for the question. You will need to check for a possible door left open to start. I would also check for air flow to the fresh food section as well. If the unit still has the wiring diagram on the back of the unit you can possibly make your checks from the control board. If not then I would check in the evaporator section for a possible defective heater, bi-metal and or sensor(possibly can check from board). You might have to defrost the evaporator to gain access to the parts. If you defrost it completely the bi-metal will show open at room temp so you will have to allow it to cool back down to test or remove and submerge in ice water to bring back down to temp to see if it closes. I would check the resistance on the sensor and the heater per the tech sheet or wire diagram.