When using the mat the most important is to monitor the bottom with a digital thermometer as this is where the frog will be and mats might make the bottom too hot, overheating and possibly burning the frog. Your ambient temperature is abit too cool though, which means the cooler area needs to be raised for a good thermal gradient, otherwise the frog may need to stay on the mat for long periods to stay warm. In this case you'd probably be better using a heat lamp during the day as this will create a warm spot and also warm the temperature of the cool side to a suitable temperature for proper themroregulation. When using the bulb, the probe can be placed on top to monitor the temperature underneath the bulb. You can probably use the mat at night for a warm area that the frog can seek out if needed.