Heat Related Illnesses
Here on the Gulf Coast we are not strangers to the extreme, summertime conditions of high temperatures coupled with high humidity. Events taking place during hot weather typically see heat illness as the bulk of the medical calls. You’ve probably way too often heard the line “it’s not the heat, it’s the humidity” — there is truth to that statement. The main mechanism for the human body to rid itself of excess heat is evaporation of sweat. When relative humidity is high, there is less capability for evaporation and therefore less cooling, increasing the risk of succumbing to heat illness.
In 1979, meteorologist Robert Steadman published two papers defining the Heat Index. The Heat Index combines temperature and humidity to give an adjustment to the temperature that reflects “how hot it feels”. The Heat Index value is calculated in the shade, but it can feel 15 ̊F hotter if you are standing in direct sunlight. Heat illness becomes likely as the heat index climbs over 100 ̊F with the risk of more severe effects increasing with higher values.
The military and industry have long been using the Wet Bulb Globe Temperature as a more comprehensive indicator of the factors affecting heat stress. In addition to temperature and humidity, it also takes into account the wind and solar radiation. While it has not been widely used in weather forecasts, it is available on an experimental basis from the National Weather Service (NWS).
There are three levels of heat illness:
Heat Cramps occur from exercising in hot conditions and are not directly caused by heat. They are marked by cramps in large muscle groups such as the legs and abdomen and is relieved by rest and hydration.
Heat Exhaustion is marked by fatigue, headache, dizziness, nausea, and/or fainting. The treatment is to immediately stop any activity, get out of the heat, cool off and rehydrate.
Heat Stroke occurs when someone ignores the symptoms of heat exhaustion and continues working in the heat. In addition to the symptoms of heat exhaustion, any altered mental state (such as confusion, difficulty speaking, erratic behavior resembling bi-polar switches or changes in consciousness), stumbling or uncharacteristic clumsiness should be considered heat stroke. The affected person needs to be removed from the heat and sun and be immediately cooled. This is a medical emergency — 911 should be called for transport to an emergency facility for evaluation. Heat stoke can cause damage to the kidneys, brain, muscles, and other body systems that may not be apparent until much later. It can also exacerbate existing, controlled illnesses.
Children, the elderly, and people with chronic ailments are at higher risk for heat illness as are those of us who spend the majority of our time in air conditioning. Ensure pets have plenty of drinking water and a shady place to rest. Never leave children or pets in vehicles as the interior temperatures may quickly climb to over 150 ̊F.
To prevent heat related illness:
- Respect the heat. Keep track of the weather and keep out of the heat in the hottest part of the day. Restrict strenuous physical activity to the morning or evening hours. Wear light colored clothing, a hat to shield yourself from the sun and use sunscreen to minimize the risk of sunburn.
- Avoid dehydration. The recommendation is to drink at least 15 oz of water before going out in the heat and 8 oz every 20 minutes during the exposure though that may not be enough. You can lose as much as a gallon per hour under extreme conditions. Drink often and drink your fill. Monitor your urine…often is good but orange is bad.
- Avoid caffeine and alcohol as they can impair the body’s ability to regulate temperature and cause added water loss via the urinary system.
- Allow proper time to acclimate to a hot environment – this may take over a week. If you’re a couch potato, spend several hours a day for a week outside to acclimate yourself prior to an event.
- Recognize your personal tolerance to heat and your medical status. Some medical conditions and medications reduce heat tolerance.
- Become familiar with the symptoms and signs of heat illnesses.
- Stop activities at the first sign of heat illness. This can be hard to discern so stay alert!
That concludes tonight’s training. Are there any questions, comments or suggested additions to this material?
Thanks, this is (callsign) clear to net control.