Knowing the heat stress index is critical for those who work outside, exposed to harsh sun and high humidity.  The heat stress index is defined as the relation of the amount of evaporation (or perspiration) required as related to the maximum ability of the average person to perspire (or evaporate fluids from the body in order to cool themselves).  When the heat stress index is high, humans can experience heat stress, which can lead to particularly dangerous conditions in which people can actually die from being too warm and unable to cool themselves properly.  Severe dehydration and even death can result from overexposure when the heat stress index is high.

Every year, athletes, construction workers and others who regularly train or work outdoors are at risk of heat stroke or other forms of heat stress thanks to a high heat stress index.  Athletes have a particularly hard time with this when training for sports during the summer time when both humidity and heat are at its peak.  It has become a rather commonplace occurrence to hear about cases where young athletes die as a result of over training in a high heat stress index environment.  This has become a concern for parents and coaches who want to ensure that their children and students will be safe.

Understanding the heat stress index and having a portable meter to measure it while you are outdoors is the key to preventing these types of deaths and overexposure.  Knowing the heat stress index can help to prevent fatigue, heat cramps, exhaustion and in some cases, even death.  In addition to careful monitoring of the heat stress index, staying hydrated and taking frequent breaks in the shade or in a cooler indoor area can help to prevent injuries and fatalities related to the sun.  Look for signs of heat emergencies in yourself and in others when working or training outdoors during times when the heat stress index is high.  Excessive flushing of the skin, dizziness, confusion and fainting are all signs that a person needs to immediately seek shade and hydration.  A heat stress monitor like the Kestrel 4400 can help you determine when the heat stress index is at dangerous levels.

It’s important for those who work with athletes and those who manage outdoor work sites to track the heat index every day, throughout the day, in order to ensure the safety of others who are onsite.  When working outdoors can’t be avoided, set up a cooling area where individuals can take breaks and rehydrate.  Possible risk factors for heat stress due to a high heat stress index include obesity, high blood pressure, dehydration and alcohol consumption.  For those who fall into any of those categories, increased hydration and more frequent breaks may be needed in order to avoid heat stress issues.

By allowing plenty of breaks and fluids throughout the day, and by avoiding work when both the sun and heat stress index are at their highest, site managers, coaches, parents, and supervisors can ensure that they are taking the proper precautions when it comes to be outdoors in hot weather.