It is dangerous to use a hair dryer to defrost a freezer because water from melting ice is likely to drip inside the dryer and electrocute the user. A person is also prone to be electrocuted while using a dryer if melting water pools around them on the floor.
Placing a bowl of boiling water inside the freezer, another method some people use to defrost the appliances, is also dangerous, as the water may slosh outside the bowl and burn the person handling it. If the person forgets to unplug the freezer before attempting to defrost it, water from the bowl might also cause electrocution.
The safest way to defrost a freezer is to unplug it, empty the contents, storing them in a cooler during the process, and allow the ice to melt on its own. It is important to place towels on the floor to absorb melting ice. Once the ice has melted, many people scrub the inside of the freezer with water and baking soda to remove any stains and lingering odors. Once the freezer is clean, it is time to plug it back in and let it cool for about 15 minutes before replacing frozen foods inside.