Infrared sensors are non-contacting sensors. As an example, if you hold up a typical infrared sensor to the front of your desk without contact, the sensor will tell you the temperature of the desk by virtue of its radiation - probably 68°F at normal room temperature.
In a non-contacting measurement of ice water, it will measure slightly under 0°C because of evaporation, which slightly lowers the expected temperature reading.
Infrared sensors are non-contacting sensors.