"If a charter flight has seats available and a resort has empty rooms, the traveller can realize fantastic savings," says Carla Lemaire, curriculum co-ordinator of the travel program at Grant MacEwan University in Edmonton.
One downside, she notes, is last-minute travellers have a limited choice of destinations. Another is travellers may not be aware of tropical diseases at sun destinations. Or they may assume they'll be immune because they'll be staying at five-star resorts or on cruise ships.
"But if you leave your hotel or ship for daytrips into wilderness areas, or consume food or beverages off-site, you may be vulnerable," Lemaire says. "Or people who prepare food at your resort may be infected."
Last-minute travellers may also think they don't have enough time to be vaccinated against tropical diseases.
A 2008 survey of 1,511 Canadians by Leger Marketing found that although 59 per cent of Canadians have taken or considered taking last-minute vacations, almost half don't think they'd have time to seek travel health advice before departure. The survey's margin of error is plus or minus 2.5 per cent 19 times out of 20.
But there's usually enough time to take precautions. Vaccines and medications preventing tropical diseases usually need to be started well in advance of departure to be effective, but accelerated dosages are available.
Hepatitis A and B both attack the liver and are major concerns for travellers. Contracted through contaminated food and water, hepatitis A requires two vaccinations. But Dr. Sarah Thrasher, medical director of the Travel Medicine and Vaccination Centre's 19 branches throughout B.C., says travellers can have the first shot the day before travel, which will help fight the disease. The second should be taken six to 12 months later.
Hepatitis B is contracted from contaminated blood and body fluids, and can result in acute liver problems. It requires three shots, "but if we're driven to it," Thrasher says, "we can give the first two shots at the same time."
Malaria is spread by infected female Anopheles mosquitoes that bite from dusk until dawn. Malaria is currently prevalent in parts of the Dominican Republic. Prevention usually means taking oral prescription medicine, starting a week or two before departure. "But daily medication can be taken, beginning the day before departure," Thrasher says.
Precautions to avoid tropical illnesses include drinking bottled water, and peeling fruits and vegetables to prevent hepatitis A; and avoiding tattoos, body piercings and unprotected sex to prevent hepatitis B and HIV.
The Anopheles mosquito feeds at night, so travellers should wear long sleeves and pants and insect repellent containing DEET on exposed flesh when outside in the evening. Pregnant women and the elderly are at risk for malaria even when taking anti-malaria medication.
There are no vaccines or medications that prevent dengue fever, a flu-like illness spread by a daytime feeding mosquito in many tropical areas. Thrasher says dengue fever is less common in coastal regions than inland, but there have been outbreaks in urban areas such as Rio de Janeiro and Buenos Aires.
"Prevention is all about protective clothing and insect repellent," she says.
She also recommends vaccinations against H1N1 and seasonal influenza for anyone travelling by airplane. "Hopefully the last-minute traveller has already had these shots," she says, "because they require some time to take effect."
Travel medical insurance is not sold at travel health clinics, but Thrasher says her staff reminds travellers of the importance of purchasing it through a travel agent or an insurance company. Travellers who find themselves in hospital abroad without medical coverage will face bills that will take a huge chunk out of their savings.
But Lemaire advises against purchasing travel insurance online. "You need to see the policy to know exactly how much coverage you're getting," she says.
"Look at the details and don't be guided by price," she adds. "If a crisis happens, you'll want the best coverage, the deluxe package that covers everything from air evacuation with a private-duty nurse to bringing your family to your bedside abroad."
She also advises against booking last-minute trips online. Licensed travel agents have access to suppliers' last-minute deals, she says, and they'll tell clients what to expect on a particular trip.
As well as pointing out health considerations, travel agents will also help you avoid other problems. "You may not realize, for example, that you can't take your child out of the country without written consent from the child's other parent," she says.
Only experienced travellers should consider online last-minute deals, says David McCaig, Vancouver-based president of the Association of Canadian Travel Agents.
"We've heard of cases in which an online company didn't inform travellers that they needed visas to enter their destination country," he says. "They bought their tickets but when they arrived at their airport, they weren't allowed to board the plane without the visa."
Before booking a trip, travellers should check the destination country's website to see if entry visas are required.
They should also check their passport's expiry date. Some countries won't admit travellers whose passports will soon need to be renewed.
Canadians living in Canada generally have to allow two weeks to pick up their passports in person after applying for them. Faster delivery may be available for those with proof of an urgent need to travel.