Safety Tidbit #38 – Spring has sprung, and things are heating up

Safety Tidbit #38 – Spring has sprung, and things are heating up

Well, Spring finally arrived here, and our temperatures are so nice we just want to be outside.  The trees are waking up, pollen is in the air, and the sound of kids playing outside (we hope) is everywhere.  As a Boy Scout, I was taught about the effects of heat and how to recognize and treat heat-related injuries (heat cramps, exhaustion, and stroke).  But why each year, do thousands of workers become sick due to exposure to heat?  Simple lack of vigilance because the effects from heat are preventable.

We’ve all taken our temperature and know that 98.6 degrees Fahrenheit is normal.  The average range for the human body is about 97 degrees to 99 degrees.  That’s a pretty narrow range, and you can see that we tolerate a lower temperature a bit better than a higher temperature.  Thermodynamics tells us that to cool or heat an object there are three basic mechanisms convection, conduction, and radiation. 

Convection, air moves over skin and heat is transferred.  If the air is hotter then heat is gained by the body when it is lower the body loses heat.  The body tries to help itself by dilating blood vessels allowing warmer blood to circulate to the skin and get cooled off.  Secondly, we secrete water to our skin so it will evaporate and as the air moves across the surface the water the vaporizes and cools us.  Approximately, 60-65 percent of our body is water and babies could be up to 75 percent. So water is pretty vital to our survival.   Quite simply, we need to sweat to cool our bodies, but we also need water (blood, etc.) to maintain most all of our bodily functions. So drinking plenty of water is important so our body. 

Conduction, I think it goes without saying to keep out of contact with hot items (e.g., stoves, furnaces, fires, etc.). However, sometimes it’s unavoidable.  When that is the case, we need to protect against the heat with barriers.  Remember, though, if we cannot sweat we will have a hard time maintaining our body temperature and we could still end up with a heat problem.  So, be careful with the use of personal protective equipment (coveralls, flame-retardant clothing, hard hats, etc.).

Radiation, remember our friend from above, the Sun?  We love the sun, but it too much of a good thing can be bad.  We need to protect from excess sun or at least the heat radiation from the sun.  The temperature around our bodies must be lower than our body temperature, so when we sweat, it takes the necessary energy to evaporate from our bodies and not from the air. We don’t need much of a temperature change, but it needs to be lower than 98.6.

The last thing we need to be aware of when it comes to heat in the workplace is our own ability to generate heat when we work.  As our body does work or exercise its core temperature rises, so it needs to get rid of that heat as well as any heat introduced by the environment. This heat load on the body can be more of an issue than the others mentioned above. Furthermore, it is affected by the fitness of the individual, age, and other medical conditions. Therefore, everyone is different.

To recap, we need plenty of water to ensure we can sweat; we need to regulate the amount of heat generated by our own bodies, and we need an ambient temperature lower than our body so it can cool itself.  So OSHA took a pretty simple stance, Water, Rest, and Shade. For further reading, check out OSHA’s heat stress web page which has much more information.

Thanks for reading and hope this was informative.  Make sure you are vigilant at every worksite.