So, you settle in for a nice soak, without a care in the world. But is there danger lurking in the water?

Well, we don’t want to be the bearers of bad news, but if that whirlpool or hot tub isn’t properly cleaned or chlorinated, you could end up with a nice body rash. The Centers for Disease Control and Prevention (CDC) reported in 2004 that “Extensive spa use combined with inadequate maintenance contribute to recreational water illnesses (RWIs) caused by pathogens such as Pseudomonas spp., and Mycobacterium spp.” Yuck.

It’s not as bad as it sounds. Pseudomonas folliculitis (hot tub folliculitis) is a skin infection that can develop within forty-eight hours after a dip in the spa. It is caused by bacteria getting into the hair follicles. You then get red, round, itchy bumps that later can develop into small pus-filled blisters. The rash usually resolves spontaneously within two to ten days.

As for the herpes question, the chlorine in hot tubs should kill the herpes virus. There are reports of people catching herpes skin infections from hot tubs, but these are very rare.

We know our response to this one is going to be greeted with howls of indignant protest from moms all over the world… But the answer is no.

There is no special “growth factor” in milk. Not that milk and other calcium-rich dairy products aren’t wonderfully nutritious. Calcium is essential for helping promote stronger bones. And if you don’t get a sufficient amount of calcium in your diet, your body compensates and basically steals it from your bones. This can eventually lead to osteoporosis-a steady, progressive loss of bone density that can cause people to become hunched over as they get older.

Height is the result of a complicated assortment of genetic factors and environmental interactions. It is polygenic-which means that many genes are involved. This is why sometime children are significantly different heights than their parents. (The legendary basketball player and sex machine Wilt Chamberlain was 7 feet 1 inch. But neither of his parents rose above 5 feet 9 inches.) And height is multifactorial. In addition to the complex genetic component, many lifestyle factors-especially the mother’s diet and health while she is pregnant and the nutrition of the child during the growth years-determine whether a person will attain his or her potential genetic height.

FYI-within the last hundred years or so, the Dutch have gone from being the shortest people in Europe to the tallest in the world. The average Dutch man today is 6 feet 1 inch. The average American man is only 5 feet 9 1/2 inches.

Height is a critically important subject for Leyner. Although he ultimately achieved the imposing stature of 5 feet 7 inches, he was a shrimp of a kid. In an autobiographical account he wrote recently for Best Life magazine, he explains that his adult obsession with weight lifting “was a long overdue response to the cumulative traumas of having been picked on as a small boy. My parents doted on me as if I were some delicate, Proustian genius prince, but once I left the cultured confines of my own home, it was Lord of the Flies out there. As my father’s career as an attorney flourished, we moved frequently, and every first day at a new school presented a mew gauntlet of bullies…” Leyner goes on to describe the following shocking scene:

“We’d just moved from Jersey City to West Orange, a seemingly benign middle-class bedroom community in the Jersey suburbs. One afternoon, on the way home from school, I’d followed a squirrel into the woods. (As an itinerant child who was typically friendless, I often found great solace in the companionship of small helpless creatures.) There I was with my fey Truman Capote blond bangs and sparkly anime eyes, and as I tried to lure the squirrel closer with a tiny marzipan banana that my mother had packed as a surprise in my lunch that day, I was set upon by a pack of boys in blue uniforms. Crazed, sadistic Cub Scouts. It was like a scene from one of those Japanese schoolboy splatter films like Kinji Fukasaku’s Battle Royale. ”

Do those instant hand sanitizers really work?

The answer is a resounding yes! Few things are as certain as this in medicine. There is no doubt that washing your hands can prevent disease.

The problem is getting people to do it. A study in the Annals of Internal Medicine looked at the rate of hand washing among physicians and found that doctors washed their hands only 57 percent of the time they should have. This is higher than many studies that have shown compliance rates lower than 50 percent. In this study, the adherence to hand hygiene rates varied by specialty with internal medicine doctors washing the most, and anesthesiologists the least. Medical students did better than their professors, and female physicians did better than their male counterparts. The presence of a hand-rub solution increased the compliance with hand washing.

For this reason, those alcohol-based hand-rub solutions are all over hospitals. The food news is that they work well too. The CDC in their Guideline for Hand Hygiene in Health-Care Settings state that “alcohol-based products are more effective for standard handwashing or hand antisepsis by health care workers than soap or antimicrobial soap.” But these hand rubs are not appropriate for use when hands are visibly soiled or after going to the bathroom.

As for the omnipresence of antibacterial soap, it is not necessary. The most important thing is to rub your hands vigorously together while washing and continue for ten to fifteen seconds. The regular soap and the scrubbing action together will help wash away the germs.

Thanks to a variety of questionable claims, the medical magnet business is booming. Annual sales are about $300 million in the United States alone and over $1 billion worldwide. Magnets have been said to increase circulation, reduce inflammation, speed recovery from injuries, relieve low back pain, and even increase longevity and aid in cancer treatment. None of these claims are supported by any data.

There are two types of magnets: static (permanent) magnets whose electromagnetic fields are unchanging (these are the ones that are marketed to gullible grandmas) and electromagnets that generate magnetic fields only when electric current flows through them. In the future, science may find roles for the use of electromagnets, but we doubt that static magnets will ever have any utility.

One best-selling author, a vociferous proponent of magnet therapy, urges us to “neutralize electromagnetic chaos.” How do you do that, you might ask? You run out and buy an Electromagnetic Chaos Eliminator Pendant, stupid. Feel free to waste $99.99 if you wish.

We think a better use of magnets is for sticking your kids’ artwork to the fridge.

This is a great question that we have been asked many times. There is a relatively simple explanation.

It’s all about the thermoregulation. Doesn’t sound very simple, does it? That’s why we’re here. Our bodies are constantly producing heat from our metabolism. This heat needs to go somewhere. Thermoregulation is the mechanism by which our body attempts to balance heat gain and loss in order to maintain a constant body temperature. This becomes more complicated when we are dealing with rising outside temperatures. It is much easier to release this heat when there is a large gradient (a bigger difference) between body and outside temperature. When it is hot outside, the body ends up having to work harder to lose heat. That makes you sweat and flush, as you try to increase blood flow to the skin and allow heat loss.

This just goes with the territory of being the warm-blooded animals that we are. Cold-blooded animals only get as hot or as cold as it is outside – which could be trouble for a rattlesnake trapped in an ice-cream truck.

So you are going bald, but trying to look on the bright side, right? You make a list of all the positives: no wasting time in the morning with hairstyling, less money spent on products, no more hat head, no dandruff, and of course, no head lice.

Well, you may not be so lucky. You don’t have to worry about the styling, the hat head, or the typical head lice, but you might still have dandruff and there are other crawling creatures that could attack your bald scalp.

There are several different types of lice: head lice (Pediculus humanus capitis), body lice (Pediculus humanus corporis), and pubic lice (Pthirus pubis). Head lice are the most common of all lice and are often seen in the heads of schoolchildren. Pubic lice are often referred to as “crabs” and body lice are known as “the cooties.” Crabs are frequently spread by sexual contact and body lice are most often found in people who don’t wash or change clothes often. In the ER, we often see homeless patients who are unfortunately infested with body lice.

Head lice probably won’t have anything to grab onto on the bald head, but body lice might spread to affect a bald head. Scabies is another creepy crawler that is often confused with body lice. Scabies is an infestation of the skin with the microscopic mite Sarcoptes scabei. These mites are much tinier than lice. You can get scabies from direct contact with a person already infested with scabies. Infestation can also occur from sharing clothing, towels, or bedding.