Compared to other parts of the world, Canada is a relatively safe place to visit. That said, wherever you are traveling, carry a medical kit that includes bandages, insect repellent, sunscreen, antiseptic, antibiotics, and water-purification tablets. Good first-aid kits are available through most outdoor shops.
It’s a good idea to get health insurance or some form of coverage before heading to Canada if you’re going to be there for a while, but check that your plan covers foreign services. Hospital charges vary from place to place but can start at around $1,000 a day, and some facilities impose a surcharge for nonresidents. Some Canadian companies offer coverage specifically aimed at visitors.
If you’re on medication, take adequate supplies with you, and get a prescription from your doctor to cover the time you will be away. You may not be able to get a prescription filled at Canadian pharmacies without visiting a Canadian doctor, so don’t wait till you’ve almost run out. If you wear glasses or contact lenses, ask your optometrist for a spare prescription in case you break or lose your lenses, and stock up on your usual cleaning supplies.
Believe it or not, AIDS and other venereal and needle-communicated diseases are as much of a concern in the Canadian Rockies  as anywhere in the world today. Take exactly the same precautions you would at home—use condoms, and don’t share needles.
Giardiasis, also known as beaver fever, is a real concern for those who drink water from backcountry water sources. It’s caused by an intestinal parasite, Giardia lamblia, that lives in lakes, rivers, and streams. Once ingested, its effects, although not instantaneous, can be dramatic; severe diarrhea, cramps, and nausea are the most common. Preventive measures should always be taken and include boiling all water for at least 10 minutes, treating all water with iodine, or filtering all water using a filter with a small enough pore size to block the Giardia cysts.
Travel through the Canadian Rockies  during winter months should not be undertaken lightly. Before setting out in a vehicle, check antifreeze levels, and always carry a spare tire and blankets or sleeping bags. Frostbite is a potential hazard, especially when cold temperatures are combined with high winds (a combination known as windchill). Most often it leaves a numbing, bruised sensation, and the skin turns white. Exposed areas of skin, especially the nose and ears, are most susceptible.
Hypothermia occurs when the body fails to produce heat as fast as it loses it. It can strike at any time of year but is more common during cooler months. Cold weather, combined with hunger, fatigue, and dampness, creates a recipe for disaster. Symptoms are not always apparent to the victim. The early signs are numbness, shivering, slurring of words, dizziness, and, in extreme cases, violent behavior, unconsciousness, and even death. The best way to dress for the cold is in layers, including a waterproof outer layer. Most important, wear headgear. The best treatment for hypothermia is to get the patient out of the cold, replace wet clothing with dry, slowly give hot liquids and sugary foods, and place the victim in a sleeping bag. Warming too quickly can lead to heart attacks.