Every cell in the human body needs water to function properly. We need water to regulate our temperature, to cushion and protect joints and organs and to help digestion move smoothly. Most of us drink at least some water every day, but now that it's summer and the mercury is rising, it's important to be more vigilant than ever. Need to raise that hydration IQ? Here are some of the most common dehydration myths -- and the facts behind them.

Myth: Dehydration is uncomfortable, but not dangerous.
Fact: While most of us will only ever experience mild dehydration symptoms like headache, sluggishness or decreased urine or sweat output, it can become severe and require medical attention. Serious complications include swelling of the brain, seizures, kidney failure and even death, according to the Mayo Clinic.

Fortunately, adults can usually nip mild or moderate dehydration in the bud with some extra fluid, according to the Mayo Clinic. But when not attended to in early stages, adults may develop extreme thirst, dizziness and confusion, and stop urinating. Symptoms should be taken even more seriously in children and older adults, according to the Mayo Clinic, especially diarrhea, vomiting, fever, inability to keep fluids down, irritability or confusion.

Myth: If you're thirsty, you're already dehydrated.
Fact: It's not too late. In fact, thirst is the body's way of telling you to drink water, and you're not at risk of becoming dangerously dehydrated the minute you feel a little parched. "When you get thirsty, the deficit of water in your body is trivial -- it's a very sensitive gauge," Dr. Stanley Goldfarb, professor of medicine at the University of Pennsylvania, told NBC in January. "It might be only a 1 percent reduction in your overall water. And it just requires drinking some fluid."

In fact, drinking when you're thirsty (sounds pretty basic, right?) is a pretty fail-proof method of staying hydrated, says Dr. Timothy Noakes, professor of exercise and sports science at the University of Cape Town in South Africa and author of Waterlogged. "You don't tell your dog or your cat when to drink, they've got a thirst mechanism," he told NBC. "Why should it be that humans should be the unique animal in the world who have to be told when to drink?"

He attributes this "you're doing it wrong" attitude largely to the bottled-water and sports drink industries. "Commercialization and industrialization have told us that humans are weak," he says, when in reality our ability to run in the heat helped us outsmart our ancient predators like lions and tigers, he says. "We should never have survived, and suddenly we're told no one knows when to drink?"

Myth: Everyone needs to drink eight glasses of water a day.
Fact: This general rule of thumb is outdated, propagated today mostly by bottled water companies. So how much do you really need to drink?

The Institute of Medicine (IOM) recommends men get roughly three liters of total beverage intake every day, and women get 2.2 liters, while others say there's no need to force water consumption if you're not thirsty.

Keep in mind those suggested intake levels include more than just water alone, says Noakes. "What you should say is glasses of fluid a day," he says, remembering to sip additional liquids the more you exercise. Coffee, tea, fruit juices, even sweetened beverages provide your body with more water -- although we wouldn't recommend the latter for hydration purposes or much of anything, really. Even food counts. About 20 percent of the average person's water intake comes from food, according to the IOM, especially from foods with high water content, like watermelon and cucumbers.

At the end of the day, how much water you should drink is extremely personal: whatever quenches your thirst.

Myth: Clear urine is a sure sign of hydration.
Fact: While keeping an eye on your urine output maybe isn't the most pleasant summer activity, it really can provide a measure of how hydrated (or dehydrated) you are, essentially in real time. But it's not clear urine that you're looking for, but rather a pale yellow. Lawrence Armstrong, Ph.D., an exercise physiologist and professor at the University of Connecticut's Human Performance Laboratory, established a urine color chart to model a measure of dehydration. Based on where you fall on the chart, you can adjust your fluid intake accordingly, the New York Times reported. (Keep in mind that certain supplements -- and foods -- can change the color of your urine.)

Myth: There's no such thing as too much water
Fact: Overhydrating can be extremely dangerous -- but it's relatively rare.

Drinking too much water leads to what's called hyponatremia, when levels of sodium in the body are so diluted that the cells begin to swell, according to the Mayo Clinic. Symptoms usually include nausea, vomiting, headache, confusion and fatigue, and can escalate to seizures and coma.

That doesn't mean don't drink when you're thirsty! It truly takes guzzling copious amounts to cause so-called water-intoxication. That's why refueling marathon runners, for example, are some of the more common hyponatremia sufferers. Of the estimated 2,600 cases of hyponatremia that have resulted in hospitalization that Noakes is aware of, he says there's "no reason they should have gotten sick." We only get ourselves into trouble when we drink beyond our thirst, he says, whether that's because of out-of-date advice or a sports drink commercial.

If you're still worried, consider this rule of thumb: Try not to drink to the point where you feel full from water alone, the Mayo Clinic reported.

Myth: Exercisers need sports drinks
Fact: If you're working out for less than an hour, water will do just fine. You don't deplete electrolyte and glycogen reserves until you've been exercising intensely for over an hour. Endurance athletes can benefit from the right mix of sugar (read: energy) and sodium, although today's sports drinks, with their miles-long ingredients list full of impossible-to-pronounce artificial additives may not necessarily be the smartest pick.

Instead, make your own! Or try some of these foods that can act as a natural alternative to sports drinks. Or consider forgoing it altogether. Many of us eat a diet so high in carbohydrates and sodium already that "replenishing" with an electrolyte drink after today's workout may just mean excreting it tomorrow, says Noakes.

Myth: Coffee dehydrates you.
Fact: Only if you overdo it. While caffeine is dehydrating, the water in coffee (and tea, for that matter) more than makes up for the effects, ultimately leaving you more hydrated than you were, pre-java. According to the Mayo Clinic, consuming 500 or more milligrams of caffeine a day -- somewhere around five cups of coffee -- could put you at risk for dehydration, but let's all agree to know when to say when.

This summer, stay hydrated but avoid over-consumption. Anything in excess can be bad for you.

By John Villalobo | Food and Health Contributor

Men and women's average stress levels may be on par with each other, but the physical and psychological toll of long-term stress on men and women is quite different.

In addition to the various health impacts of stress experienced by both sexes, tension and anxiety can also take a different toll on the male mind and body, starting with the immediate stress response. While stress tends to activate the "tend and befriend" response in women, men have been found to react to stress more with the aggressive "fight or flight" response, according to one study.

"When the fight or flight response is activated [in both sexes], our bodies go into emergency mode and take care of immediate and acute needs, focusing on getting energy to the muscles, and we don't take care of the longer-term needs of the body," stated Dr. Emma Acosta, who specializes in physical-therapy and sports medicine. "We shut down things like our immune systems, reproductive systems ... It does suppress the release of testosterone and it suppresses other reproductive systems. The wear and tear on the body is severe from repeated stress."

For men, there are several reasons why stress stinks and should simply be avoided if possible.

1. Decreased Facial Attractiveness

The male hormone, testosterone, has been linked with a strong immune system and facial attractiveness in men. A University of Toronto study in which women ranked the attractiveness of 97 men found that those with higher testosterone and lower levels of the stress hormone cortisol had higher immune system responses, and were deemed the most attractive. Men with higher cortisol levels, in turn, were deemed less attractive. Cortisol, the study suggests, may play a role in blocking testosterone's appeal to potential mates.

2. Early Heart Disease Risk As A Result Of Inherited Stress

An extensive body of research has established that stress is a risk factor in the development of heart disease, and inherited stress can also increase the risk of early heart disease. Recently, a Henry Ford Hospital study found that men with a family history of heart disease had a diagnosis of heart disease an average of 12 years earlier than those without a family history. They were also more likely to have a higher stress symptom score (an evaluation based on worry, impatience, anger and other symptoms) than men without a family history of heart disease -- suggesting that the propensity to get stressed may be, to some degree, inherited.

“Depression and stress are known risk factors for heart disease, and they both have strong heritability,” lead author Mark W. Ketterer, Ph.D., of Henry Ford Hospital’s Department of Behavioral Health, said in a May 2013 press release. “None of the other risk factors, including high cholesterol, high blood pressure or diabetes, were shown to have a significant familial link in this group. Therefore, it’s likely that men who have an early onset of heart disease might have a genetic predisposition to stress, which causes the heart disease.”

3. Leaves A Mark On Sperm & Offspring Development

Here's a big incentive for future fathers to start de-stressing: research in animals suggests that chronic stress could result in gene expression changes to dad's sperm -- and those changes could manifest in his offspring in the form of a muted reaction to stress.

"It didn't matter if dads were going through puberty or in adulthood when stressed before they mated. We've shown here for the first time that stress can produce long-term changes to sperm that reprogram the offspring HPA stress axis regulation," lead researcher Tracy L. Bale, Ph.D., said in a university press release. "These findings suggest one way in which paternal-stress exposure may be linked to such neuropsychiatric diseases."

4. Accelerates Prostate Cancer Development.

A recent study on mice found chronic stress to accelerate the development of prostate cancer, suggesting that prostate cancer patients could benefit from stress reduction as part of their treatment.

University of California studies have demonstrated that stress management can yield positive results in men with prostate cancer.

5. Erectile Dysfunction.

According to WebMD, 10 to 20 percent of all cases of erectile dysfunction (ED) are linked to psychological factors like stress, anxiety and depression. Sasha M. Samorski, Ph.D., professor of neurology at Stanford, explained that turning on the parasympathetic nervous system (also known as the "relax and renew" system) is essential for arousal -- but when we're stressed, we're operating from the sympathetic nervous system ("fight or flight").

"You have trouble having an erection in the first place because you can't establish that parasympathetic tone," said Samorski in a 2012 talk for the Science of a Meaningful Life series. "[Or] you manage to have an erection ... and you accelerate the transition from parasympathetic to sympathetic, and the whole thing goes too quickly."

6. Lower Sperm Count.

Stress and anxiety could play a large role in male fertility, according to new research. Recent studies conducted in Italy found that men who were stressed ejaculated less and had a lower sperm count and concentration than those who were not under stress. Stress was also positively correlated with deformed and less mobile sperm.

7. Social Withdrawal.

The stereotype of the "strong and silent type" may actually be a picture of the male stress response. A 2010 University of Southern California study found that men who are stressed out exhibit less activity in the brain regions associated with understanding others' feelings. When placed under acute stress, the men had less of a brain response to facial expressions, especially fear and anger, whereas women had greater activity in these brain regions.

“These are the first findings to indicate that sex differences in the effects of stress on social behavior extend to one of the most basic social transactions -- processing someone else’s facial expression,” Mara Mather, director of the Emotion and Cognition Lab at USC, said in a press release. “Under stress, men tend to withdraw socially while women seek emotional support."

Both men and women can benefit from scientifically-proven stress busters like running, yoga, meditation or deep breathing. And to combat work-related stress, exercise can be one of the best forms to take control of every day life's tedious components.