"Each year, from 2013 to 2015, portable heater fires in residential buildings -- a subset of heating fires in residential buildings -- accounted for an estimated average of 1,650 fires in the U.S. These fires resulted in an annual average of 90 deaths, 175 injuries, and $84 million in property loss. The term 'portable heater fires' applies to those fires that are caused by catalytic heaters, oil-filled heaters, or other heaters, such as electric heaters, that are designed to be carried or moved for use in a variety of locations. Portable heaters are a subset of space heaters -- small heaters designed to heat specific areas or rooms of a building. While portable heater fires in residential buildings were small in number, representing only 4 percent of all heating fires in residential buildings, their consequences were substantial: they accounted for 43 percent of fatal heating fires in residential buildings. Moreover, many of these fires were preventable, as human error was a contributing factor to the fire. For example, placing the heater too close to combustible items or leaving the heater unattended."
U.S. Fire Administration: http://www.usfa.fema.gov/
Topical Fire Report Series (October 2017), v.18 no.8