The aim of this study is to develop a postlaryngectomy airway climate explorer (ACE) for assessment of intratracheal temperature and humidity and of influence of heat and moisture exchangers (HMEs). Engineering goals were within-device condensation prevention and fast response time characteristics. The ACE consists of a small diameter, heated air-sampling catheter connected to a heated sensor house, containing a humidity sensor. Air is sucked through the catheter by a controlled-flow pump. Validation was performed in a climate chamber using a calibrated reference sensor and in a two-flow system. Additionally, the analyser was tested in vivo. Over the clinically relevant range of humidity values (5-42 mg H2O/l air) the sensor output highly correlates with the reference sensor readings (R2 > 0.99). The 1-1/e response times are all <0.5 s. A first in vivo pilot measurement was successful. The newly developed, verified, fast-responding ACE is suitable for postlaryngectomy airway climate assessment.