2.2. Temperature Humidity Index

The temperature humidity index (THI) was calculated using the following equation: (1.8 × T_db + 32) − [(0.55 − 0.0055 × RH) × (1.8 × T_db − 26)] [8,14], where T_db is the dry-bulb temperature (°C), and RH is the relative humidity (%). The temperature and humidity inside the chambers were controlled using an automatic computerized system. In the automatic chambers, the ambient temperature and humidity were fixed at 25 °C and 35–50%, respectively (low-temperature, low-humidity, LTLH), and 31 °C and 80–95%, respectively (high-temperature, high-humidity, HTHH).