Purchase your balloons within two to three hours before you will use them. Helium-filled balloons start to slowly deflate beyond that time frame.
Put the balloons in the vehicle's back seat, being sure they are attached to a balloon weight. Never put helium-filled balloons in your trunk; the heat on a hot day and other objects in the trunk may cause balloons to pop or deflate.
Cover the balloons with a large trash bag when you have a large quantity or if the weather is bad. Have someone hold the trash bag open upside down, and allow the balloons to float up into the trash bag. Pull the draw strings on the trash bag to tighten around the balloons, and let the strings hang down. This will keep rain and wind from damaging the balloons as well as keep them intact during your travel.
Order your balloons at a location not too far from the party or event. Remember that you cannot take helium-filled balloons on an airplane, and there may be limitations to how many you can bring onboard a bus or train.
