Most Kestrel Meters which report temperature & humidity also have the capability of reporting the heat stress index. The meters below are popular with our professional customers who rely on using heat stress index to even more specialized readings including WBGT and THI (5400) in their job functions. The 5400 series meters are dedicated heat stress meters with audible and visual warnings which not only report heat stress but also Wet Bulb Globe Temperature without the need for distilled water or a bulky globe. For our cattle ranchers check out the Kestrel 5400AG Heat Stress Tracker. With the 5400AG you will get, Heat Load Index (HLI), Temperature-Humidity Index (THI), Accumulated Heat Load Units (AHLU), Wet Bulb Globe Temperature (WBGT), heat index, Delta T, temperature, humidity and much more. 21 measurements in all! The Kestrel 5400AG Cattle Heat Stress Tracker is designed to help you MEASURE and MANAGE your herd’s heat stress, ensuring you MAXIMIZE your bottom line. Click here for the entire Kestrel Agriculture Line of Meters. For our firefighter friends check out the Kestrel 5400FW Fire Weather Meter Pro. The Kestrel 5400FW Pro measures Wet Bulb Globe Temperature (WBGT), Probability of Ignition (PIG), Fine Dead Fuel Moisture (FDFM), temperature, barometric pressure, humidity and much more. 20 measurements in all! Click here for the entire Fire Weather Line of Meters.