Surface

• Space heaters are meant to be kept on hard, flat surfaces, especially during operation. These appliances should be kept high enough to keep them beyond the reach of young children and household pets.
  
  

Monitoring

• Space heaters should be monitored at all times while in use. Never use a space heater while you are sleeping or outside of the room.
  
  

Materials

• All combustible materials are to be kept a minimum of three feet away from the front of the heater, and should not come in contact with the sides or back of the space heater. This includes materials such as clothing, furniture, curtains and bedding, as well as such flammable materials as fuel, matches, lighters or paint cans.
  
  

Extension Cords

• Extension cords should be avoided at all costs. If you must use an extension cord for your space heater, however, you should ensure that its power rating is equal to or higher than that of the space heater itself. Cords should be kept loose, and on top of any carpeting or rugs. Plugging other objects into the same extension cord as a space heater could cause the unit to overheat.
  
  

Moisture

• Unless a space heater has been specially designed for use in outdoor or wet conditions, never use it in an area that is prone to moisture or wetness. Doing so could damage your space heater.
  
  

Legality

• Some space heaters, specifically those that operate on kerosene fuel, may be illegal. Some states, such as Massachusetts, has banned the sale and use of kerosene heaters altogether. Even if it is legal in your state, it may be illegal or banned in certain applications. For example, Iowa State University has banned the use of all space heaters on university-owned property; kerosene or electric.
  
  

Fuel

• If your space heater runs on any type of liquid fuel, make sure you fill it with the correct type of fuel every time. Avoid overfilling the tank, and use a towel to wipe away any spilled fuel before starting your space heater.
  
  

Supplementary

• Space heaters are only meant for temporary use in areas that aren't reached by a building's normal heating system. Space heaters should never be used as a replacement for any building's heating system.