No, you cannot mix hot and cold water in a cold fill washing machine. Cold fill washing machines are designed to be connected to the cold water supply only. The machine controls the temperature of the water by using its internal heating element (if available) or by relying on the temperature of the cold water alone.
If you try to mix hot and cold water by manually connecting both hot and cold water supplies to a cold fill washing machine, it can cause potential damage to the machine and disrupt its proper functioning. Mixing hot and cold water could lead to incorrect water temperature settings, affect the performance of the detergent, or even damage the internal components of the machine.
It's important to follow the manufacturer's instructions and guidelines for your specific washing machine model. If you require warm or hot water for your laundry, you should consider a washing machine that supports hot fill or has a built-in water heater.