The fluoroptic measurement method, recently developed by Wagenaar and coworkers to determine in a contactless manner the temperature of moving particles, has been improved. It now has a higher accuracy (approximately 5%) and can be used for particles that move at higher speeds. In addition, the technique has become much less labor-intensive. Validation has been realized by comparing experimentally determined heat-transfer coefficients for a cylinder in crossflow with predictions of several well-known correlations from the literature. A consistent deviation of less than 10% is observed This comparison therefore shows the reliability of the fluoroptic measurement method.