YAVAPAI COUNTY -- The threat of excessive heat in the Verde Valley will continue until 8 p.m. Monday night, according to the National Weather Service.
Afternoon high temperatures will range from 105-115 degrees. Overnight lows will still average in the mid-70s to low 80s.
The Weather Service warns people to slow down this weekend. People recreating or working outdoors and those without access to air conditioning face an elevated risk of heat-related illness.
Depending upon the amount of exposure and the health of an individual, heat illness can range from mild to fatal. That is not an idle threat. Heat kills more people every year than all floods, hurricanes, tornadoes put together, according to livescience.com
Summer heat is the most dangerous weather phenomenon residents face in Arizona, said Ken Waters of the Weather Service in Phoenix.
Dr. Jacob Shank, an emergency room physician at the Sedona and Verde Valley Medical Centers said the numbers for those who get heat stroke are serious. In older populations, he said the risk of fatality is 30 to 60 percent. Even among children, the factor is 1-15 percent fatality potential.
"We see the visitor population more often with heat-related problems," said Dr. Shank. "Among the older population, it is often related to humidity. That is why you her more stories about those problems in Texas, Louisiana, in the southern tier of states. But, when you get above 110 degrees, it doesn't matter how humid or dry it is. It's hot."
Shank explained that there are four ways the body has of getting rid of excess heat: conduction, convection, radiation and evaporation.
"When your body heats up, you want to dissipate that heat. But, as the ambient temperature gets higher than our body heat at 98.6 degree, then conduction, convection and radiation go away. The outside temperature is hotter than our body anyway and you can't lose your heat to an even hotter environment. The only way left to dissipate that heat is through evaporation or sweating. That's why in the hotter environments, you lose a lot of your body's regulatory mechanisms. You add humidity in there and it is also harder to lose heat by sweating, too."
The best option, Shank advised, is good old water. Hydrate both before and during your exercise or activity.
"Remember, it is a lot easier to stay ahead of heat-related symptoms than to try to catch up after you are already experiencing symptoms," said Shank.
When outdoors in the summer heat, you should have a liter to a liter and a half of some type of fluid. The health guidelines for children recommend 3 to 8 ounces of fluids every 20 minutes. For adolescents to adults, it is a liter to 1.5 liters every half hour.
There are now dozens of hydration options.
Drinking lots of water is not the entire solution. Athletes or those doing a lot of exertion should also consume fluids with salt or electrolytes, like sports drinks, because in addition to losing water, you are also losing sodium, potassium and other trace minerals.
Many high school sports coaches will have salt tablets in their medical kits. One commercial product, Gatorade, is among the sports drinks that is made with glucose, which is a co-factor for absorption of a lot of those electrolytes.
"You need glucose rather than fructose to absorb electrolytes," said Shank. "So it's better to have those simple sugars."
As you are sweating, your sweat has good content of salt. You will notice that when you go to a cooler environment, salt crystals will dry on your skin, so you will want to add supplement drinks.
Many people deal with the effects of heat exertion without the aid of medical professionals.
"The frequency of heat-related emergencies coming into the ER is not high." said Shank. "We will see 20 to 30 people each year come into the emergency departments. But, there are probably many more that are treated at home."
What is heat stroke?
Shank explained that, "If normal body temperature is 98.6 degrees, the definition of heat stroke is when the body temperature is greater than 104. That high temperature is combined with neurologic symptoms such as confusion, headaches, irritability or irrational behavior. With some people, the first time they may see symptoms may be at that point. People with heat stroke are in bad condition and are brought in by ambulance."
"Some people walk into the ER and tell me that they think they have heat exhaustion or stroke. But, if they are able to tell me that, their condition is probably not as serious. That is not to say you don't have heat-related illness or dehydration."
"That is the reason you hear stories of people dying on trails every year is because they are hiking alone and they don't have the great thermos-regulatory systems in place. By the time you get to an altered mental status or confusion, you don't have the presence of mind to call 911 on your own anyway.
When people are brought in, it is often a loved one or an employee of a skilled nursing facility."
But, there are often other symptoms that come from heat exhaustion.
"Heat greater than body temperature, but less than 104 degrees is heat exhaustion. At this point you will have profuse sweating, weakness or fatigue, you feel exhausted, have nausea and vomiting, Shank said.
Also heat cramps will be common in young athletes.
"Heat rash is typically found among young kids, blocking of the sweat glands with heavy sweating. That's not as serious or it is a benign condition. Treated by getting out of the heat."
There are other things that can trigger heat problems or make them worse. the doctor said alcohol, caffeine and sugar all can dehydrate you
Shanks said when he worked in Las Vegas, "These are the things that will cause dehydration and make you more susceptible."
Shank talks about the giant Electric Daisy Carnival, better known as EDC this weekend in Las Vegas, a huge rave with hundreds of acts on five stages running 24 hours a day in the middle of summer heat. He said people are using alcohol, ecstasy and red bull and "that's what we would see all the time, is dehydration and heat related illnesses."
"I worked two years at Burning Man and it is the same thing there. You get in those hot conditions and you add in caffeine, energy drinks, alcohol and it's just a recipe for disaster."
Often people don't get around to reporting their illness until they have gone over the edge.
"Symptoms of heat exhaustion, feeling fatigued, tingly... as soon as you get to those kind of things, you should get out of the sun, get into a cool place, wet yourself down with wet towels and things and start drinking water and Gatorade."
An ounce of prevention is worth a pound of cure and it's safer to be prepared on a trail. So if you get to the point, where you recognize you have half your water left, that would be an excellent time to turn around and head back.
If you are on a trail and run out of water, look for sources of water. There will be concerns if the water is safe to drink, but if you are dealing with these kind of symptoms, you can deal with sanitary conditions later on. Look for shade and take it easy. If there is a 15-percent mortality rate, you want to deal with what would kill you first.
And don't ever leave children or pets in a closed car.
Temperatures in parked vehicles rise 20 degrees in the first 10 minutes, potentially reaching 130 degrees in that time. Temperatures in this range can cause serious illness or death.