The present study aimed to investigate correlations between the environmental variables, coat characteristics, and physiological responses of Caracu young bulls. Forty-eight Caracu young bulls (mean±SD: 283±23 days old; 240±38 kg body weight) participated in the experiment conducted at Sertãozinho, Brazil, in October 2025, on two days separated by a 13-day interval. Data collection was conducted in the morning and lasted approximately 2 h 30 min. Data on the variables sweating rate (g/m²/h), respiratory rate (num./min), and rectal temperature (°C) were collected and the exact time at which each animal was sampled was recorded. Then, these data were combined with the relative humidity (RH, %), air temperature (AT, °C), and the Temperature and Humidity Index (THI) of that moment. Thermal environment variables at each 20 min point were obtained from the local weather station (CIIAGRO). Data were analyzed using descriptive statistics, non-parametric tests, and correlation analysis. During data collection, the mean AT was 28°C (range: 23.3-30.7°C), UR averaged 49.7% (range: 33.8-75.7%), and ITU averaged 76.4 (range: 70-79.9). The sweating rate showed a positive correlation with rectal temperature (r=0.30; p=0.005), AT (r=0.39; p<0.001), and THI (r=0.32; p=0.002) and a negative correlation with RH (r=-0.27; p=0.01). The respiratory rate showed a positive correlation with rectal temperature (r=0.22; p=0.04) and a negative correlation with RH (r=-0.30; p=0.004), indicating that higher humidity tends to reduce heat loss through respiratory pathways. The results highlight the relevance of the thermoregulatory behaviour of Caracu cattle under tropical conditions. Selecting animals with efficient physiological responses, along with strategic management during high-THI periods, can contribute to resilience and productive efficiency in tropical beef cattle farming. We conclude that young Caracu bulls are affected by a challenging thermal environment and activate physiological responses that are also influenced by environmental conditions. Sweating rate and respiratory rate responses were found to decrease with increasing relative humidity.