Health concerns should comprise an important piece of your preparation for a trip to Vietnam, and staying healthy on the road takes vigilance. Make it a priority. Tropical heat and mosquitoes are the biggest dangers, other than motor vehicle accidents, and travelers should exercise caution over the extreme change in diet and sanitary standards in Vietnam -- especially if eating at local joints. But with just a few pretrip precautions and general prudence, you can enjoy a safe and healthy trip. Consult with a health practitioner or someone specializing in travel health before your trip about inoculations. Stay abreast of international monitors, such as the U.S. Centers for Disease Control and Prevention (tel.877/FYI-TRIP [394-8747]; www.cdc.gov) or the International Association for Medical Assistance to Travelers (IAMAT; tel. 716/754-4883, or 416/652-0137 in Canada; www.iamat.org) for tips on travel and health concerns, as well as the most current information on any outbreaks of infectious diseases in the region.

General Availability of Healthcare -- The only high-quality healthcare facilities are located in Hanoi and Ho Chi Minh City (Saigon). Hanoi and Ho Chi Minh City each have a branch of the International SOS clinic. Hanoi also supports the Hanoi Family Medical Practice, as well as the Hanoi French Hospital. Your options in rural areas are quite limited, and any major medical issue usually means an uncomfortable transfer to one of these centers or an evacuation to Singapore, Bangkok, or Hong Kong.

In rural areas, the local apothecary shop often acts as a catchall triage for what ails you, and over-the-counter medications are available anywhere from small storefront pharmacists who, with little more than a brief chat and description of a problem (with the use of a phrase book or some creative charades), will dole out affordable prescriptions for anything from antibiotics to sleeping pills. However, there are a lot of fake medicines for sale, and storage conditions may be poor. I would recommend calling SOS, Family Practice, or your home country's embassy for recommendations of reliable pharmacies.

When you're far from good healthcare, I recommend bringing a small kit of medicines that includes antidiarrhea medication, rehydration salts for the ubiquitous bout with the trots, antibacterial cream and bandages, and a pain reliever like ibuprofen or acetaminophen.

Common Ailments

Tropical Illnesses -- Most of the real "baddies" in Vietnam and Cambodia are tropical diseases carried by mosquitoes: the likes of malaria, dengue fever, and Japanese encephalitis. Quite simply, the best way to avoid mosquito-borne diseases is to avoid being bitten. Repellents that contain between 25% and 50% DEET are the most effective. The more gentle alternatives, including oil of eucalyptus (look for baby-care products in any pharmacy) provide terrific DEET-free mosquito protection but are not as effective. A new product on the market, picaridin, also offers DEET-free protection. It's an excellent repellent, but at 7% concentration, it may last for a shorter period of time. Also be aware that malaria mosquitoes bite most frequently around dawn and dusk, so exercise caution especially at those hours (wearing long sleeves and long trousers and burning mosquito coils is a good idea). Dengue-fever mosquitoes bite during the day. Always sleep under a mosquito net where needed -- and if they are needed, they are usually provided -- and make sure it has no holes (or at least patch them up with tape). If you are purchasing your own mosquito net, it is most effective if it has been pretreated with permethrin, which is a very safe insecticide.

Malaria -- Three hundred million people are infected with malaria yearly, with over one million deaths, particularly in developing countries. The disease has four strains, including deadly cerebral malaria (common in Africa), but all are life threatening. Malaria is caused by a one-cell parasite transmitted by the female Anopheles mosquito. The parasite travels into the liver, lies dormant, and grows; then symptoms occur when the parasite enters the bloodstream. Symptoms include high fever, painful headaches in the front of the head, nausea, vomiting, dizziness, and confusion. If experiencing any degree of these indicators, seek treatment. Keep in mind that malaria symptoms look like a number of diseases (even just a flu).

Malaria is a concern for travelers in Vietnam. But don't stress out over the bogus information you might hear and read -- the kind of stuff that would keep you up all night listening for skeeters or vacationing somewhere else. Arm yourself with correct information, and forget the rest.

First, know that visitors to the major cities and standard coastal tour areas in Vietnam have a very low chance of contracting malaria -- very low. Travelers venturing off the track and up into the bush in the Central Highlands or the interior in the central, north, or Mekong Delta will want to take a malaria prophylaxis. A standard course of mefloquine (brand name Lariam) or atovaquone/proguanil (brand name Malarone) will cover you. In farther "off-the-track" border regions near Myanmar, Laos, and Cambodia -- areas where a resistance to standard medications has developed -- travelers should take Doxycycline.

Your best insurance is to take care when sleeping: Ensure that windows are closed (when you have air-conditioning) and that you have a good mosquito net when needed (typically provided). Also, cover up in Vietnam -- wear a long-sleeve shirt and trousers in the evening; this not only keeps the mosquitoes at bay, but moderate attire is also the social norm in conservative Vietnam (and also much cooler in the hot months). Put bug spray (preferably with DEET) on exposed areas of the skin, and avoid swampy marshes or heavy jungle at dawn and dusk. Don't let fears of malaria ruin your trip, and don't buy into the paranoia going around. Take these precautions -- as needed -- and all will be well.

However, no antimalarial drug is 100% effective. If you develop fever and chills while traveling or after your return home, seek medical care and tell the provider that you have traveled to a malarious area and need to be checked.

Dengue Fever -- Dengue fever is possible to contract just about anywhere in Southeast Asia. Dengue is a viral infection spread by the Aedes-Aegypti mosquito. Symptoms include headache, high fever, and muscle pain. Unlike malaria and Japanese encephalitis, which survive and spread mostly out in rural areas, dengue knows no bounds and urban outbreaks are common. There is no prophylaxis and no treatment -- and some cases are fatal -- but with dengue, it is just a matter of suffering it out with cold compresses, fever-reducing pain relievers, and lots of hydration. A real drag.

Japanese Encephalitis -- Japanese encephalitis is viral, transmitted by mosquitoes, and is endemic to the region -- especially after rainy season (July-Aug). Symptoms include headache, fever, nausea, upset stomach, and confusion -- all quite similar to malaria and dengue fever. When outbreaks occur, or if traveling widely in rural parts, vaccination is recommended, but note that vaccination is not 100% effective.

Hepatitis -- Another common but preventable ailment in Vietnam is hepatitis A, which causes inflammation of the liver. Hepatitis A is contracted from contaminated water or food, and the pathogen of hep A is rather stalwart, staying alive in the air and on the skin for some time. The best preventative is to wash your hands thoroughly before eating and stick to bottled water and food cooked to order (not sitting out). Symptoms include fever, general ill health (nausea and vomiting), lack of appetite, and jaundice.

For anyone over the age of 2 traveling in Vietnam, I'd recommend a hepatitis A vaccination. The inoculation requires just one shot and a booster after 6 months.

Hepatitis B is contracted through contact with blood of an infected person (needle, sexual contact, splashed blood, or even sharing a toothbrush or razor -- insist on a new razor if you get a haircut and shave). Nurses, for example, are commonly immunized in any country, and the three shots (over a 6-month period) are recommended for a longer stay in the region.

Rabies -- Rabies is a fatal viral infection carried by animals. The disease is transmitted by a bite or contact with the saliva of an infected animal. Rabies is a concern in rural Vietnam, among populations of dogs, as well as monkeys and bats. If exposed in any way -- a puncture wound of any kind from a suspected animal who exhibits strange behaviors such as foaming at the mouth or ataxia -- seek treatment immediately and follow a series of vaccinations over a 1-month period -- commonly the Verorab brand. Adventure travelers or health workers who will spend lots of time in the countryside and the bush might just want to consider a pre-exposure vaccination, which makes post-exposure treatment far more simple, as it decreases the number of shots required as well as prevents the need for rabies immune globulin, which may not be available and thus may require a trip elsewhere for care (for example, Bangkok). Another group at high risk is children. They are more likely to touch or play with stray dogs and are less likely to report a bite.

Typhoid -- A bacterial illness that is transmitted through contaminated food, typhoid is life threatening, especially to children and the elderly, but early detection and a course of antibiotics is usually enough to avoid any serious complications. There are a few different vaccinations available in both oral and injectable forms. Though they are only between 55% and 70% effective, the vaccine is recommended for travelers in the region.

Tuberculosis -- As in so many developing countries, tuberculosis is quite common, especially in rural Vietnam. Caused by poor hygiene and unventilated overcrowding, TB is a bacterial infection of the lungs that can spread to other parts of the body and, if left untreated, kill. The vaccination requires a TB screening 6 months prior to inoculation.

Sexually Transmitted Diseases -- Anyone contemplating sexual activity in Vietnam should be aware that HIV, the virus that causes AIDS, is rampant in many Southeast Asian countries, including Vietnam. Also concerning are other sexually transmitted diseases (STDs), such as gonorrhea, syphilis, herpes, and hepatitis B. A latex condom is recommended second to abstinence. For more information on AIDS, see the AIDS sidebar below.

AIDS in Vietnam -- Statistics on AIDS in Vietnam are unreliable because of limited testing, but with increased border crossings from China and rampant prostitution -- including, sadly, a great deal of child prostitution -- the prognosis is not good. Estimates report that about 0.5% of the general population in Vietnam is infected with HIV. However, this proportion can be much higher in commercial sex workers (possibly up to 60%-70% in some areas) and intravenous drug users (possibly up to 60%-80% in some areas).

Unprotected sex with an anonymous partner is very risky behavior. Although condoms are widely available in Vietnam, be aware that certain groups still have very high HIV/AIDS infection rates. International monitors with the U.S. Centers for Disease Control and Prevention and other agencies are working with the Hanoi government on HIV/AIDS prevention, care, and treatment. An increasing campaign is promoting the use of condoms -- you'll see lots of signs with cartoon character condoms smiling and waving from the roadside, needle users underneath skull and crossbones, or a happy young couple embracing, a condom in the young man's hand. But generally speaking, Vietnam's remaining fears of outside influence and continued tight control on information -- combined with a certain shame over even talking about issues of sex -- are ripe ground for the disease to spread. Time will tell.

Other Diseases -- Other diseases common in the region include schistosomiasis and giardia, both of which are parasitic diseases that can be contracted from swimming in or drinking from stagnant or untreated water in lakes or streams. Cholera epidemics sometimes occur in remote areas. Keep an eye on the CDC website or other international health monitors to stay informed of any health hot spots.

Dietary Red Flags

Unless you intend to confine your travels to the big cities and dine only at restaurants that serve Western-style food, you'll likely sample some new cuisine. Initially, this could cause an upset stomach or diarrhea, but it usually lasts just a few days as your body adapts to the change in your diet.

Always drink bottled water (never use tap water for drinking). To be safe, you should even brush your teeth with bottled water. The old adage of "Boil it, cook it, peel it, or forget it" is important to remember in Vietnam. Be sure to peel all fruits and vegetables and avoid raw shellfish and seafood. Also beware of ice unless it is made from purified water. Any suspicious water can be purified by boiling for 10 minutes or treating with purifying tablets. If you're a vegetarian, you will find that Vietnam is a great place to travel; vegetarian dishes abound throughout the region (just say Toi ahn jai, which means "I eat vegetarian").

In terms of hygiene, restaurants are generally better options than street stalls. But don't forgo good local cuisine just because it's served from a cart or dining is on squat stools at street side -- this is where you'll find some of the best food in Vietnam, as well as the highest likelihood of a stomach cootie. It is acceptable -- in fact, customary -- to wipe down utensils in restaurants, and in some places locals request a glass of hot water for just that purpose. Carrying antiseptic hand-washing liquid is also not a bad idea.

So how can you tell if something will upset your stomach before you eat it? Trust your instincts. Avoid buffet-style places, especially on the street, and be sure that all food is cooked thoroughly and made to order. I've been plenty sick my share of times and have found that each time I get into trouble, I've usually felt a certain sense of dread from the start. If your gut tells you not to eat that gelatinous chicken foot, don't eat it. If your hosts insist but you're still nervous, explain about your "foreign stomach" with a regretful smile and accept a cup of tea instead. Be careful of raw ingredients, common as garnish on Vietnamese dishes. Questions like, "Are these vegetables washed in clean water?" are inappropriate anywhere. Use your best judgment or simply decline.

Bugs, Bites & Other Wildlife Concerns

All kinds of creepy critters live in a tropical climate. Mosquito nets in rural accommodations are often required and, if so, are always provided by hoteliers. Check your shoes in the morning (or wear sandals) just in case some little ugly thing is taking a nap in your Nikes. Keep an eye out for snakes and poisonous spiders when in jungle terrain or when doing any trekking. Having a guide doesn't preclude exercising caution. Rabies is a concern in rural areas of Vietnam, and extreme care should be taken when walking rural roads, especially at night, when you might want to carry a walking stick or umbrella as a deterrent to any mangy mutts. Vietnamese street mutts, the ones who escape the stew pot, have all been hit with stones; if you are threatened by a dog, the very act of reaching to the ground for a handful of stones is often enough to send the beast packing. Some travelers, especially those spending a lot of time in the back of beyond, get a rabies pre-exposure vaccine. If you are bitten, wash the wound immediately and, even if you suffer just the slightest puncture or scrape, seek medical attention and a series of rabies shots (now quite a simple affair of injections in the arm in a few installments over several weeks). The best advice: Stay away from dogs.

Respiratory Illnesses

SARS hit the region hard in the winter and spring of 2003. Singapore reported some cases and essentially closed to tourism, and though most other countries in the region reported no cases of the disease, places like Thailand, Vietnam, and Cambodia suffered the fallout of the region-wide scare. At press time, there are no new cases in the region.

Following right on the heels of the SARS crisis, which was devastating to tourism in Vietnam, the avian influenza, also called the "bird flu," caused another public-relations nightmare throughout the region. The danger of humans contracting bird flu is still rather low, and limited to people working in poultry slaughterhouses. Millions of chickens suspected of carrying the illness have been culled, and the countries affected have been unusually forthright about reporting new cases and combating outbreak. Human-to-human transmissions -- caused by a mutation of the poultry-borne disease -- have not been reported. For more information, check the CDC website for the most up-to-date information about the disease. It is important to note that you cannot contract bird flu from consuming cooked chicken.

Air quality is not good in the larger cities like Ho Chi Minh City, Hanoi, Haiphong, and Danang; with no emissions standards, buses, trucks, and cars belch some toxic stuff. Visitors with respiratory concerns or sensitivity should take caution. Tuberculosis is a concern in more remote areas where testing is still uncommon.

Sun/Elements/Extreme Weather Exposure

Sun and heatstroke are a major concern in Vietnam. Locals wear those cool conical hats and long-sleeve shirts and trousers for a reason. Limit your exposure to the sun, especially during the first few days of your trip and, thereafter, from 11am to 2pm. Use a sunscreen with a high protection factor and apply it liberally. Asian people are still big fans of parasols, so don't be shy about using an umbrella to shade yourself (all the Buddhist monks do), but note that it is a decidedly feminine choice of accessory. Remember that children need more protection than adults.

Always be sure to drink plenty of bottled water, which is the best defense against heat exhaustion and the more serious, life-threatening heatstroke. Coffee, tea, soft drinks, and alcoholic beverages should not be substituted for water; they are diuretics that dehydrate the body. In extremely hot and humid weather, try to stay out of the midday heat, and confine most of your daytime traveling to early morning and late afternoon. If you ever feel weak, fatigued, dizzy, or disoriented, get out of the sun immediately and go to a shady, cool place. To prevent sunburn, always wear a hat and apply sunscreen to all exposed areas of skin.

Be aware of major weather patterns; many island destinations are prone to typhoons or severe storms.

What to Do If You Get Sick Away from Home

Reliable emergency service is limited to Hanoi and Ho Chi Minh. Any foreign consulate can provide a list of area doctors who speak English. If you get sick, consider asking your hotel concierge to recommend a local doctor or nearby pharmacist. Some larger hotels and resorts have on-call nurses and doctors available for "room calls." Do not get involved with local hospitals, many of which have an archaic standard of care, unless in the most dire situation or as a base for an evacuation.

For travel abroad, you may have to pay all medical costs upfront and be reimbursed later. Medicare and Medicaid do not provide coverage for medical costs outside the U.S. Before leaving home, find out what medical services your health insurance covers. To protect yourself, consider buying medical travel insurance. (For information on traveler's insurance, trip cancellation insurance, and medical insurance while traveling, please visit www.frommers.com/planning.)

Very few health insurance plans pay for medical evacuation back to the U.S. (which can cost $10,000 and up). A number of companies offer medical evacuation services anywhere in the world. If you're ever hospitalized more than 150 miles from home, MedjetAssist (tel. 800/527-7478; www.medjetassistance.com) will pick you up and fly you to the hospital of your choice virtually anywhere in the world in a medically equipped and staffed aircraft 24 hours a day, 7 days a week. Annual memberships are $225 individual, $350 family; you can also purchase short-term memberships.

U.K. nationals will need a European Health Insurance Card (EHIC) to receive free or reduced-cost health benefits during a visit to a European Economic Area (EEA) country (European Union countries plus Iceland, Liechtenstein, and Norway) or Switzerland. The European Health Insurance Card replaces the E111 form, which is no longer valid. For advice, ask at your local post office or see www.dh.gov.uk/travellers.

If you suffer from a chronic illness, consult your doctor before your departure. Pack prescription medications in your carry-on luggage, and carry them in their original containers, with pharmacy labels -- otherwise, they won't make it through airport security. Carry the generic name of prescription medicines, in case a local pharmacist is unfamiliar with the brand name.