Hello, dear readers!

We're on the cusp of summer and that means it's our duty as doctors (and mothers) to remind you to please protect yourselves and your family against the sun as you spend more time outdoors, and against the ticks and mosquitos the season always brings. We've written about this before, but if you have any new questions or need clarifications, please drop us a line.

A column in which we addressed the topic of hackers interfering with the proper workings of wireless medical devices, such as pacemakers, got a lot of response. Many readers found it extremely unsettling, and honestly, we're right there with you. The good news, as we said in the column, is that despite how easy television dramas and films make this type of hacking appear, it's actually quite difficult. But if you're worried enough to want to take preventative measures, a letter from a physician in Spokane, Washington, offers an interesting option. His inspiration comes from the range of RFID-blocking products now available to fend off electronic snoops and pickpockets. In this case, the answer is a special vest.

"The vest is lined with metallic mesh to block potential 'pinging' and the theft of personal information," he wrote of a garment he saw in a travel store. "It occurs to me that these would also block 'Bluetooth' and other RF signals being used to hack an internal medical device. It would be simple for a cardiologist to verify this. Simply obtain a vest, have it in the office and when patients come in for modification of settings on an implanted defibrillator or pacemaker, have them wear the vest first, and see if it blocks the modification."

In response to a column about how noise pollution adversely affects health, a reader from Oklahoma asked us to recommend a set of noise-canceling headphones. Because everyone's needs are so different, we suggest scanning the selections from online retailers, like Best Buy, Amazon, Costco and the like. What we find to be helpful about shopping online for items like these are the many reviews posted by fellow shoppers. They can give you a good sense of what each product can (and can't) do, and often answer detailed questions from fellow shoppers, all of which can help you to find the right device for your specific needs.

We'll wrap up with a question stemming from our column about the measles vaccine. A couple who are headed to Paris this fall (lucky you!) ask whether they should get vaccinated for measles. Because you indicate that you both had measles as children, the answer is no. According to guidelines set by the Centers for Disease Control and Prevention, you are considered to be protected from measles if you have either already had the disease or have already received the appropriate doses of the vaccine. Boosters of the measles vaccine are not needed. If you're not sure whether you're protected, you can find out with a simple blood test.

Thank you again for all of your letters. We hope you have a great summer and look forward to continuing this conversation next time.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: I am a 64-year-old male in good health, although I have a bit of a gut in the middle. My issue is that I have developed an umbilical hernia that looks like a large "outie." It is not very attractive, but it is not causing any pain or discomfort. What course of action should I take?

Dear Reader: Umbilical hernias, or so-called "belly-button hernias," are quite common. They occur because of tissue weakness at the umbilical ring. The weakness allows the contents within the abdomen to bulge into the opening, thus making an "innie" appear like an "outie." In children with umbilical hernias, the hernia develops because of incomplete closure of the belly-button (umbilicus) at birth. In adults, umbilical hernias develop because of increased pressure within the abdomen that stretches and weakens the tissue (fascia) at the umbilicus. Increased pressure in the abdomen can be caused by obesity, pregnancy or fluid in the belly from diseases such cirrhosis or ovarian cancer.

Umbilical hernias are three times more common in women than in men. The material that typically bulges within a hernia is fat from the abdomen and the lining of the abdominal cavity. In the majority of people, the herniation doesn't hurt. However, when the lining of the abdominal cavity (the omentum) becomes stuck within a hernia, the area can become painful. Even worse is when the small intestine becomes stuck. Called an incarcerated hernia, this compression leads to a loss of blood flow to the intestine, which can cause severe pain, altered bowel movements and possible death of the bowel tissue. The omentum and the intestine are more likely to become entrapped in men. Women more commonly have umbilical hernias that are reducible, meaning the material that pushes into the hernia can easily be moved back into the abdomen.

A small umbilical hernia without symptoms doesn't require treatment. That changes if a hernia causes pain or is not reducible. For a small, symptomatic hernia, a surgeon cuts into the skin and locates the hernia sac. He or she then removes the sac or pushes it back into the abdomen; sutures the surrounding fascial layers together; and thus closes the area of weakness. With a larger hernia, a surgeon will have difficulty bringing together the surrounding fascial layers. This is when he or she will place a mesh over the defect and attach the mesh to the surrounding fascial layers. Unless the hernia is very large (more than 9 centimeters in size), a surgically repaired hernia is unlikely to recur or cause pain.

Because of the lack of symptoms from your hernia, you're unlikely to need surgical treatment. But you should be on the alert for pain in the umbilical area and for difficulty pushing the hernia back in to the abdomen. Either problem is a sign that surgery might be needed.

Also, you might be able to decrease pressure on the abdomen by decreasing your "gut in the middle." Improving your diet by cutting back on sugar, exercising and losing weight will put less pressure upon the hernia and may decrease the likelihood of ever needing hernia surgery.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My dad and brothers are hunters, so there's always deer meat in the freezer and it's often on the menu. But I'm hearing that it's now linked to a brain disease. Should we be worried?

Dear Reader: You're referring to chronic wasting disease, also known as CWD, which has now been found in deer herds in at least 23 states. It has also been identified in moose, elk and reindeer, and is a becoming a problem in Canada, Norway and South Korea as well.

Chronic wasting disease is a progressive disease that affects the functioning of the brain and spinal cord of the infected animals, and invariably leads to their death. Although it is highly contagious among animals -- the disease continues to spread in wild deer herds and fenced-in hunting ranches -- there are no known cases of transmission to humans at this time.

CWD is part of a family of disorders known as prion disease. If that sounds familiar, it's because prions play a leading role in mad cow disease. The disease created an uproar when it was identified in Great Britain, Europe and the United States in the late 1980s through the early 2000s. Mad cow caused several hundred deaths in humans, mostly in Great Britain, and resulted in 4.5 million cows being destroyed.

Although prions are normal proteins found in the brains and nervous systems of most animals, including mammals, reptiles and birds, the prions involved in the disease process behave abnormally. They start a chain reaction among the normal proteins in the brain, causing them to fold and bend and become deformed. This prevents the proteins from fulfilling their specific biological purposes, and ultimately results in the characteristic spongy appearance in the brain tissues of the infected animal. In CWD, prions cause numerous small holes to develop in the brains of infected deer, which affect the deer's behavior and lead to death.

Symptoms in infected deer include tremors, loss of coordination, weight loss and wasting, a lack of awareness of the surroundings, an uncharacteristic loss of fear of humans, and increased thirst, urination and salivation. The incubation period of CWD is quite long, averaging from 18 to 24 months. That means an animal can be infected with the disease but not show any ill effects. CWD is transmitted among herds of deer through normal contact, like touching noses, licking, mating and giving birth. In addition, soil contaminated by the urine, feces or carcass of an affected animal remains a vector of infection for more than a decade.

CWD was first identified in the late 1960s, but as we mentioned earlier, there are no known instances of transmission to humans. However, because mad cow made the leap to humans, scientists are now investigating whether the same thing can happen with CWD. Wildlife officials in Colorado and other heavily affected states are urging hunters to bring their deer in for testing before consumption. This involves an analysis of tissues from the brain and lymph nodes. The agency that issued your hunting permit will have complete information.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)