The Kestrel 4400 Heat Stress Tracker detects when conditions are not safe, even before your body does.Building on a Tradition of Accurate Rugged Environmental Measurements
NK has been researching, developing and manufacturing technically advanced environmental instruments for more than fifteen years and owns multiple patents on their unique features. Kestrel Weather and Environmental Meters are employed by thousands of users in hundreds of demanding activities around the world. Every Kestrel meter is pocket-sized, rugged, accurate, waterproof, easy-to-use and backed by an industry-leading five-year warranty. Every Kestrel meter is designed, developed, built, tested and supported entirely in the USA. NK is proud to be both a recognized leader in Lean manufacturing and process improvement and an award-winning top workplace.
Human Heat Illness is Dangerous, Deadly and on the Rise!
Athlete deaths from heat exposure are on the rise. Warming summers have been accompanied by weekly reports of athletes young and old collapsing from severe heat-induced illness. Our military training units struggle to keep soldiers healthy while preparing them for the grueling heat of Iraq and Afghanistan.OSHA is campaigning to prevent heat illness in outdoor workers and reports that every year thousands of workers become sick working in the heat, and some even die. In every instance, accurate and localized measurement of heat stress conditions is a key component of a heat illness prevention plan. The Kestrel 4400 Heat Stress Tracker, new from NK, answers this need.
Human heat stress results from a combination of many environmental factors – air temperature and humidity along with radiant heat from the sun and surfaces, balanced by the cooling effect of breezes or air flow. Anyone who has stood under welcome shade adjacent to a sizzling parking lot understands that these conditions must be evaluated exactly where peoples’ activities are taking place. The most common composite measurement used to determine appropriate exposure to heat stress conditions is Wet Bulb Globe Temperature or “WBGT.” The American College of Sports Medicine, the American Conference of Governmental Industrial Hygienists, and the US Military all have published threshold limit values (TLV’s) or reference guidelines for conditions, activity levels and hydration based on WBGT, clothing levels and acclimatization of participants.
The Kestrel 4400 Heat Stress Tracker Provides Waterless WBGT Measurement
Until now, most accurate WBGT measurement tools were large, cumbersome to use (requiring the transport of distilled water along with the measurement unit) and/or expensive. NK added a compact black globe thermometer to the already proven sensor suite of the Kestrel 4000 Pocket Weather Tracker, then built in advanced algorithms to calculate WBGT values within 2.18 deg C of the values obtained from a full-sized WBGT setup. The Kestrel 4400 Pocket Heat Stress Tracker fits in a pocket or small Kestrel Belt Carry Case and provides accurate waterless WBGT measurements within minutes of exposure to the air.
TWL and Other Key Measurements
The Kestrel 4400 also displays thermal work limit (“TWL”), another recognized composite heat stress prediction tool. For both WBGT and TWL, the Kestrel 4400 provides on-screen alarms when conditions enter the caution and danger zones, providing clear and immediate guidance that heat illness prevention steps must be taken. Clothing levels can also be customized, making the Kestrel 4400 particularly useful in activities requiring heavy protective gear which worsens heat stress. The Kestrel 4400 also displays natural wet bulb temperature, black globe temperature, and mean radiant temperature (“MRT”).
Generally leaves the warehouse in 2-4 business days


*offer valid for this product only and can not be applied to other products.