Do your motors draw only 180mA each when they are working? Then they are not high torque, they are just little motors.
The datasheet for the L298 shows a max saturation voltage drop when the load current is 1A. Your load current is 360mA for each of the 4 outputs so the saturation voltage drop for each output might be 1.2V. Then each output causes heating of 0.36A x 1.2V= 0.43W and the L298 heats with a total of 0.43W x 4= 1.72W.
The datasheet shows that without a heatsink its chip heats 35 degrees C above the ambient temperature for each Watt. So the temperature rise is 1.72W x 35 degrees= 60.2 degrees. If the ambient temperature is 30 degrees C then the chip is 90.2 degrees C which is pretty darn hot.
Why don't you bolt a heatsink to the metal tab on the L298N IC? Or do you have the L298P in the tiny surface-mount package that will get much too hot unless it is fastened somehow to a heatsink?