Beat the heat of the “Dog Days of Summer”

By Jeff Hutchins, Industrial Hygiene Technical Advisor

We know that the “dog days of summer” are typically the hottest, most humid days of the year.  But did you ever wonder how they got their name?

According to the Farmers’ Almanac[1], the name originated during ancient Roman times.  In the Northern Hemisphere, the star Sirius prominently occupies the same region of the sky as the Sun in late summer.  Sirius is part of the constellation Canis Major, the Great Dog.  The Romans believed this bright star added to the sun’s heat during the time when Sirius is most visible (roughly July 3 – August 11); hence the “dog days” of summer.

While the origin of the name is rooted in mythology, the truth is that when sweltering weather arrives, the dangers of heat-related illnesses are very real.  When the combination of environmental conditions [temperature + humidity + air movement]and physical exertion result in your body producing more heat that it can release through sweating and respiration, your core temperature can rise to unsafe and unhealthy levels.  Symptoms can range from mild (Heat Exhaustion) to life-threatening (Heat Stroke).  It doesn’t matter if you’re in your backyard, on the playing field or at work, identifying a potential heat stress situation and taking prompt action is the key.  The National Institute for Occupational Safety and Health (NIOSH) and the University of Washington both have excellent resources for identifying and treating heat illnesses.

OSHA Heat Safety ToolPreparing yourself for the heat is an often overlooked step.  Watching the weather forecast, getting enough rest, being properly hydrated, avoiding caffeine & alcohol and dressing appropriately are all steps that minimize the risk of developing a heat illness.  Scheduling strenuous activities earlier in the day can reduce your risk as well.

The Occupational Safety & Health Administration (OSHA) has a Heat Safety Tool app that calculates the heat index for your location and, based on the heat index, displays a risk level for outdoor activity. Then, with a simple “click,” you can get reminders about the protective measures that should be taken at that risk level to protect yourself from heat-related illness.

While a dog may be man’s best friend, having human companions watching out for each other during hot weather is important, too.  Being alert to the signs & symptoms of heat illness in family members, teammates and co-workers, and checking on vulnerable friends and neighbors, like the elderly or those with chronic illnesses, are all steps we can take to keep everyone safe in the heat.

Heat Safety Pic 2And finally, take a tip from our canine friends: when it gets too hot, take a big drink of water and find a cool spot to rest.


[1] Why Are They Called “Dog Days” of Summer? (2015)   Retrieved 9 June 2016 from Farmers’ Almanac online.

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