Inferring from the infrared image, the temperature of the top of the radiator is approximately:

To provide a detailed analysis, it would be helpful to have the specific infrared image or the temperature readings that are discernible from it. Infrared images typically show thermal emissivity and can indicate temperature through color gradients.

If you're analyzing an infrared image of a radiator, here's how you might approach inferring the temperature:

1. Understanding Color Gradients: In the infrared spectrum, different colors represent different temperature ranges. Warmer temperatures might appear in shades of red or yellow, while cooler areas could appear in blue or green. Identify the color coding used in the image.

2. Reference Points: Often, infrared images include reference temperature points. Determine if the image has a scale that correlates certain colors with temperature values.

3. Estimation: If you know what the radiator's surface should typically be (for example, a standard temperature for a heated radiator), you can make an estimation based on the color and the reference points.

4. Measurement Tools: If the image is analyzed using software, there might be a tool to measure temperature directly from the image.

Without the infrared image or specific details, it's challenging to provide an exact temperature. However, if you have access to the image or additional data, those would be essential for an accurate assessment.