Dry ice usually comes in 10 by 2 inches (25. 4 cm × 5. 1 cm) squares weighing about 10 pounds (4. 5 kg). You’ll need one square for every 15 inches (38 cm) of cooler length. [2] X Research source You can make your own dry ice by spraying a CO2 fire extinguisher into a pillowcase for 2-3 seconds. Wear gloves, closed-toe shoes, and other protective gear if you try this yourself.
If your cooler doesn’t have a valve, leave the top open slightly. [3] X Research source Plastic and styrofoam coolers are common options for storing dry ice.
Close the lid securely after filling the cooler.
If you don’t have room in your trunk, make sure you roll down your windows or set your air conditioner to circulate fresh air from outside. [9] X Research source
Never dispose of dry ice in a sewer, sink, toilet, or garbage disposal. It can freeze and rupture the pipes, and may even lead to an explosion if the dry ice expands too quickly.
