U.S. Department of Homeland Security • U.S. Fire Administration

National Fire Data Center • Emmitsburg, Maryland 21727

www.usfa.dhs.gov/statistics/reports/index.shtm

Topical Fire Report Series Volume 10, Issue 3 / January 2010

Portable Heater Fires in Residential Buildings 

These topical reports are designed to 

explore facets of the U.S. fire problem as 

depicted through data collected in the U.S. 

Fire Administration’s (USFA’s) National Fire 

Incident Reporting System (NFIRS). Each 

topical report briefly addresses the nature 

of the specific fire or fire-related topic, highlights important findings from the data, and 

may suggest other resources to consider for 

further information. Also included are recent 

examples of fire incidents that demonstrate 

some of the issues addressed in the report or 

that put the report topic in context.

Findings

■ An estimated 3,800 portable heater fires occur annually in the United States.

■ Only 2 percent of residential building heating fires involve portable heaters, but these fires 

account for 25 percent of fatal residential building heating fires.

■ Residential building portable heater fires peak in February (21 percent).

■ Thirty-four percent of residential building portable heater fires occur in bedrooms. Of these 

fires, 23 percent are started by bedding such as blankets, sheets, and comforters.

■ Fifty percent of the residential building portable heater fires occur because the heat source is 

too close to combustibles. 

From 2005 to 2007, portable heater fires in residential 

buildings—a subset of residential building heating 

fires—accounted for an estimated average of 3,800 fires 

in the United States each year. These fires resulted in an 

average of approximately 115 deaths, 250 injuries, and 

$98 million in property loss.1,2,3 The term portable heater fires

applies to those fires that are caused by catalytic heaters, 

oil-filled heaters, or other heaters that are designed to be 

carried or moved for use in a variety of locations.4

 Portable 

heaters are a subset of space heaters—small heaters designed to 

heat specific areas or rooms of a building.5

This topical report addresses the characteristics of residential building portable heater fires reported to the National 

Fire Incident Reporting System (NFIRS) between 2005 

and 2007. For a broader overview of heating fires, see the 

companion topical report, Heating Fires in Residential Buildings

(Volume 10, Issue 2).

While residential building portable heater fires are small 

in number, representing only 2 percent of all residential 

building heating fires, their consequences are substantial: 

they account for a quarter (25 percent) of fatal residential 

building heating fires. Moreover, many of these fires are 

preventable as human error—placing the heater too close to 

combustible items or leaving the heater unattended—was a 

contributing factor to the fire.

For the purpose of this report, the term “residential portable heater fires” is synonymous with “residential building 

portable heater fires” as residential heating fires commonly 

mean those fires caused by heating that occur in buildings. 

“Residential portable heater fires” is used throughout the 

body of this report; the findings, tables, charts, headings, 

and footnotes reflect the full category, “residential building 

portable heater fires.”

Type of Fire

Building fires consist of two major categories of incidents: 

fires that are confined to specific types of equipment or 

objects (confined fires) and those that are not (nonconfined 

fires). Confined building fires are small fire incidents that 

are limited in scope, confined to noncombustible containers, rarely result in serious injury or large content losses, 

and are expected to have no significant accompanying 

property losses due to flame damage.6,7 Very few residential 

portable heater fires are confined fires—less than 1 percent.

The few fire incident records coded as “confined” residential portable heater fires in NFIRS had sufficient data to be 

included in the overall analyses. As a result, the remainder 

of this report will address all combined residential portable 

heater fires and will not distinguish between confined and 

nonconfined fires.

Table 1 presents losses, averaged over this 3-year period, for 

residential fires and portable heater fires reported to NFIRS.8

continued on next page
TFRS Volume 10, Issue 3/Portable Heater Fires in Residential Buildings Page 2

Table 1. Loss Measures for Residential Building Portable Heater Fires 

(3-year average, 2005–2007)

Measure Residential 

Building Fires

Residential Building 

Heating Fires

Nonconfined Residential 

Building Heating Fires

Residential Building 

Portable Heater Fires

Average Loss:

Fatalities/1,000 Fires 5.4 1.9 14.4 28.4

Injuries/1,000 Fires 28.1 9.3 53.8 95.8

Dollar Loss/Fire $14,560 $3,540 $25,490 $34,810

Source: NFIRS 5.0.

Notes: Average loss for fatalities and injuries is computed per 1,000 fires; average dollar loss is computed per fire and is rounded to the nearest $10.

When Residential Building Portable 

Heater Fires Occur

As shown in Figure 1, residential portable heater fires are 

relatively constant throughout the day with some variations. 

They are generally at their lowest in the early mornings, 

roughly between 2 a.m. and 7 a.m., and peak from 10 

a.m. to 12 p.m. This latter 2-hour period accounts for 12 

percent of residential portable heater fires.9

 

Figure 1. Residential Building Portable Heater Fires by Time of Alarm (2005–2007)

Source: NFIRS 5.0.

Figure 2 shows the pattern of residential portable heater 

fires reported to NFIRS throughout the year. As would 

be expected, the number of portable heater fires increases 

during the late fall and winter months (November through 

March), peaking in February. They are most prevalent 

during the winter months of December through February 

when the use of portable heaters is most common. From 

March to August, fires decline from 12 percent to less than 

1 percent. Residential portable heater fires are uncommon 

in the summer months.
TFRS Volume 10, Issue 3/Portable Heater Fires in Residential Buildings Page 3

Figure 2. Residential Building Portable Heater Fires by Month (2005–2007)

Source: NFIRS 5.0.

Fire Spread in Residential Building 

Portable Heater Fires

Just over half of residential portable heater fires (51 percent) remained confined to the object or room of origin 

(Figure 3). When compared to other residential heatingrelated fires, residential portable heater fires tend to spread 

further through the home. Forty-nine percent of residential 

portable heater fires spread beyond the object or room of 

fire origin; by contrast, only 34 percent of nonconfined 

residential heating fires (excluding portable heaters) spread 

beyond the room of origin. This increased fire spread may 

be, in part, why residential portable heater fires tend to be 

more serious as evidenced in the loss measures of Table 1.

Figure 3. Extent of Fire Spread of Residential Building Portable Heater Fires (2005–2007)

Source: NFIRS 5.0.
TFRS Volume 10, Issue 3/Portable Heater Fires in Residential Buildings Page 4

Items First Ignited in Residential Building 

Portable Heater Fires

Twenty-eight percent of items first ignited in residential 

portable heater fires fall under the “soft goods, wearing apparel” category (Figure 4). This category includes 

bedding, curtains, and clothing. “Structural component 

or finish” accounts for another 28 percent of residential 

portable heater fires. “Furniture and utensils” is the third 

leading category at 18 percent.

Figure 4. Items First Ignited in Residential Building Portable Heater Fires (2005–2007)

Source: NFIRS 5.0.

Of the fires that occur in bedrooms, bedding, such as blankets, sheets, and comforters, is the leading item first ignited 

by portable heaters. These bedding items account for 23 

percent of the residential portable heater fires that originate 

in the bedroom. Clothing not on a person accounts for 

another 15 percent.

For residential portable heater fires that occur in common 

rooms, 19 percent are started by upholstered sofas and 

chairs too close to the portable heater. Floor coverings 

such as rugs, carpets, or mats account for an additional 17 

percent.

Factors Contributing to Ignition

Table 2 shows the leading factors contributing to ignition 

of residential portable heater fires. Placing a heat source too 

close to combustible objects was the leading contributing 

factor (50 percent). Unattended equipment was a contributing factor in 12 percent of residential portable heater 

fires and electrical failure or malfunction was a contributing 

factor in 9 percent of the fires. These 3 contributing factors 

played a role in 71 percent of residential portable heater 

fires. 
TFRS Volume 10, Issue 3/Portable Heater Fires in Residential Buildings Page 5

Table 2. Leading Factors Contributing to Ignition for Residential Building Portable Heater 

Fires (Where Factor Contributing Specified, 2005–2007)

Factor Contributing to Ignition Percent of Residential Building Portable Heater Fires

(Unknowns Apportioned)

Heat source too close to combustibles 50.2

Equipment unattended 11.6

Unspecified electrical failure, malfunction 9.0

Unspecified mechanical failure, malfunction 6.5

Unspecified short-circuit arc 5.2

Source: NFIRS 5.0.

Notes: 1) Includes only incidents where factors that contributed to the ignition of the fire were specified. 

2) Multiple factors contributing to fire ignition may be noted for each incident. 

Where Residential Building Portable 

Heater Fires Start

One- and two-family residences are disproportionately 

represented in residential portable heater fires. One- and 

two-family residences account for 88 percent of residential 

portable heater fires—yet they represent only 66 percent of 

residential fires. Multifamily dwellings account for an additional 9 percent of portable heater fires. Multifamily dwellings, especially older apartments, condominiums, and the 

like often have building-wide heating systems and the need 

for portable heaters may be less, perhaps accounting for the 

differences in portable heater fire incidence. 

Most residential portable heater fires start in bedrooms (34 

percent) or common rooms including dens, family rooms, 

living rooms, and lounges (20 percent). Fires that start in 

other function or activity areas account for 8 percent of fires 

(Table 3).

Table 3. Leading Areas of Fire Origin in Residential Building Portable Heater Fires 

(2005–2007)

Area of Origin

Percent of Residential Building 

Portable Heater Fires

(Unknowns Apportioned)

Bedrooms 34.4

Common room, den, family room, living room, lounge 20.1

Other function areas 8.1

Bathroom, checkroom, lavatory, locker room 7.2

Substructure area or space, crawl space 5.1

Source: NFIRS 5.0.

Suppression/Alerting Systems in 

Residential Building Portable Heater Fires

Smoke alarms were present in 41 percent of residential portable heater fires. Smoke alarms are known to have operated 

in 24 percent of portable heater fires. Smoke alarms were 

not present in 32 percent of residential portable heater fires 

(Table 4). In another 27 percent of these fires, firefighters 

were unable to determine if a smoke alarm was present. 

Of the residential portable heater fires where a smoke alarm 

was present, the alarms failed to operate in 21 percent of 

the incidents.

Note that the data presented in Table 4 are the raw counts 

from the NFIRS data set and not scaled to national estimates 

of smoke alarms in residential portable heater fires.
TFRS Volume 10, Issue 3/Portable Heater Fires in Residential Buildings Page 6

Table 4. NFIRS Smoke Alarm Data for Residential Building Portable Heater Fires 

(NFIRS, 2005–2007)

Presence of 

Smoke Alarms Smoke Alarm Operational Status Smoke Alarm Effectiveness Count Percent

Present

Fire too small to activate smoke alarm 27 2.1

Smoke alarm operated

Smoke alarm alerted occupants, occupants responded 222 17.0

Smoke alarm alerted occupants, occupants failed to respond 10 0.8

No occupants 43 3.3

Smoke alarm failed to alert occupants 10 0.8

Undetermined 22 1.7

Smoke alarm failed to operate 111 8.5

Undetermined 83 6.4

None present 414 31.7

Undetermined 354 27.1

Null/Blank 9 0.7

Total Incidents 1,305 100.0

Source: NFIRS 5.0.

Notes: The data presented in this table are raw data counts from the NFIRS data set. They do not represent national estimates of smoke alarms in residential building portable heater fires. They are presented for 

informational purposes. Total may not add to 100 percent due to rounding.

Full or partial Automatic Extinguishing Systems (AESs) were 

present in less than 1 percent of residential portable heater 

fires. This finding is not surprising since only 3 percent of 

nonconfined residential building fires, where the data are 

available to analyze, have an AES present. 

Note that, as in the smoke alarm data, the data presented in 

Table 5 are the raw counts from the NFIRS data set and not 

scaled to national estimates of AESs in residential portable 

heater fires.

Table 5. NFIRS Automatic Extinguishing 

System (AES) Data for Residential Building 

Portable Heater Fires (2005–2007)

AES Presence Count Percent

AES present 9 0.7

Partial system present 1 0.1

AES not present 1,243 95.2

Undetermined 43 3.3

Unknown (blank or null entry) 9 0.7

Total Incidents 1,305 100.0

Source: NFIRS 5.0.

Notes: The data presented in this table are raw data counts from the NFIRS data set. They do not represent national estimates of AESs in residential building portable heater fires. They are presented 

for informational purposes. Total may not add to 100 percent due to rounding.

Examples

These recent examples of residential portable heater fires 

illustrate issues and concerns associated with these fires—

unattended equipment left too close to combustibles—and 

the damage they cause. These incidents were captured from 

local media reports.

•	 December 2007: A kerosene space heater caused a fire 

that displaced four people from a townhouse in Suffolk, 

VA. The portable heater was left unattended and it 

ignited nearby objects in the living room. No one was 

hurt in the fire, but it did cause major property damage estimated at $48,000. The fire prompted city fire 

officials to issue safety guidelines for the use of portable 

heaters.10

•	 January 2008: Firefighters were called to a fire that 

killed one man in Lexington, NC. Fire officials reported 

that the fire was caused by a portable heating device that 

was left too close to a couch.11

•	 November 2008: Firefighters were called to a fire in a 

mobile home in South Haven, MI. The fire began after 

a portable heating device ignited nearby combustible 

materials. Firefighters reported that there were no working smoke alarms in the mobile home. The fire claimed 

the life of a 19-year-old woman.12

•	 December 2008: A three-alarm fire broke out at a 

neighborhood church in Lawrence, MA on Christmas 

day. The fire was most likely started by an electric space 

heater [portable heater] left plugged in. The fire caused 

$200,000 in damage. No one was hurt in the fire and 

firefighters had control of the fire within 20 minutes.13

continued on next page
TFRS Volume 10, Issue 3/Portable Heater Fires in Residential Buildings Page 7

Conclusion

Residential building portable heater fires are a small but 

damaging subset of residential heating fires. The number 

of residential heating fires has decreased over the past few 

decades due to safer heating equipment and better public 

education about the dangers and prevention of heating 

fires. Despite the decrease in overall heating fires, portable 

heater fires still remain a serious problem. An estimated 

3,800 residential portable heater fires occur each year in the 

United States. Many of these fires and resulting damage can 

be prevented by moving portable heaters away from nearby 

combustible materials and turning the heater off when not 

in the room or area.

Many homes have installed central heating systems but 

portable heaters are still used to augment heating systems 

in cooler areas of the home or for early or unexpected cold 

weather. The challenge for communities and the fire service 

is to emphasize heating fire prevention and safe use and 

maintenance of portable heating equipment.

NFIRS Data Specifications for Residential 

Building Portable Heater Fires

Data for this report were extracted from the NFIRS annual 

Public Data Release files for 2005, 2006, and 2007. Only 

version 5.0 data were extracted.

Residential building portable heater fires were defined as:

•	 Incident Types 111, 112, 114, 116, 120-123:14

Incident Type Description

111 Building fire

112 Fires in structure other than in a building

114 Chimney or flue fire, confined to chimney or flue

116 Fuel burner/boiler malfunction, fire confined

120 Fire in mobile property used as a fixed 

structure, other

121 Fire in mobile home used as fixed residence

122 Fire in motor home, camper, recreational 

vehicle

123 Fire in portable building, fixed location

Note that Incident Types 114 and 116 do not specify if 

the structure is a building.

Incident Type 112 is included as previous analyses 

have shown that Incident Types 111 and 112 are used 

interchangeably.

•	 Structure type:

– 1 - Enclosed building

– 2 - Fixed portable or mobile structure

– Structure type not specified (null entry)

•	 Aid types 3 (mutual aid given) and 4 (automatic aid 

given) were excluded to avoid double counting of 

incidents.

•	 Property use 400 to 464:

Property Use Description

400 Residential, other

419 One- or Two-family dwelling

429 Multifamily dwelling

439 Boarding/Rooming house, residential hotels

449 Hotel/Motel, commercial

459 Residential board and care

460 Dormitory-type residence, other

462 Sorority house, fraternity house

464 Barracks, dormitory

•	 The USFA cause hierarchy was used to determine residential building heating fire incidents.15

•	 Equipment involved in ignition codes 141 to 143:

Equipment 

Involved in 

Ignition

Description

141

Heater; includes floor furnaces, wall heaters, 

and baseboard heaters; excludes hot water 

heaters

142 Heater, catalytic

143 Heater, oil-filled

•	 Equipment portability code 1 was used to identify 

portability.

To request additional information or to comment on this 

report, visit http://www.usfa.dhs.gov/applications/feedback/index.jsp
TFRS Volume 10, Issue 3/Portable Heater Fires in Residential Buildings Page 8

Notes: 

1 National estimates are based on 2005 to 2007 native version 5.0 data from the National Fire Incident Reporting System 

(NFIRS) and residential structure fire loss estimates from the National Fire Protection Association’s (NFPA) annual surveys 

of fire loss. Fires are rounded to the nearest 100, deaths to the nearest 5, injuries to the nearest 25, and loss to the nearest 

$million.

2 In NFIRS, version 5.0, a structure is a constructed item of which a building is one type. In previous versions of NFIRS, the 

term “residential structure” commonly referred to buildings where people live. To coincide with this concept, the definition 

of a residential structure fire for NFIRS 5.0 has, therefore, changed to include only those fires where the NFIRS 5.0 structure type is 1 or 2 (enclosed building and fixed portable or mobile structure) with a residential property use. Such fires are 

referred to as “residential buildings” to distinguish these buildings from other structures on residential properties that may 

include fences, sheds, and other uninhabitable structures. In addition, incidents that have a residential property use, but do 

not have a structure type specified are presumed to be buildings.

3 Residential buildings include, but are not limited to, one- or two-family dwellings, multifamily dwellings, boarding houses 

or residential hotels, commercial hotels, college dormitories, and sorority/fraternity houses.

4 For purposes of this analysis, residential building portable heater fires are defined as those residential buildings (defined 

above) for which the cause of the fire was determined to be portable heaters.

5 Space heaters may be fixed (stationary) or portable. Space heaters typically include heating and wood stoves; heaters 

(including portable kerosene heaters, portable electric heaters, oil-filled heater, and catalytic heaters); local furnaces; and 

fireplace inserts.

6 NFIRS distinguishes between “content” and “property” loss. Content loss includes loss to the contents of a structure due to 

damage by fire, smoke, water, and overhaul. Property loss includes losses to the structure itself or to the property itself. Total 

loss is the sum of the content loss and the property loss. 

7 In NFIRS, confined fires are defined by Incident Type codes 113 to 118.

8 The average fire death and fire injury loss rates computed from the national estimates above will not agree with average 

fire death and fire injury loss rates computed from NFIRS data alone. The fire death rate computed from national estimates 

would be (1,000*(115/3,800)) = 30.3 deaths per 1,000 residential building portable heater fires and the fire injury rate 

would be (1,000*(250/3,800)) =65.8 injuries per 1,000 residential building portable heater fires. 

9 For the purposes of this report, the time of the fire alarm is used as an approximation for the general time the fire started. 

However, in NFIRS, it is the time the fire was reported to the fire department.

10 “Heater blamed in Suffolk fire that displaced four,” www.hamptonroads.com, December 4, 2007. 

http://hamptonroads.com/2007/12/heater-blamed-suffolk-fire-displaced-four (accessed April 30, 2009). 

11 “Portable Heating Device Cause in Fatal Fire,” WXII12.com, January 8, 2008. http://www.wxii12.com/print/15004655/

detail.html (accessed April 30, 2009).

12 “Home apparently lacked working smoke detectors,” www.mlive.com, November 24, 2008. 

http://www.mlive.com/news/kzgazette/index.ssf?/base/news-31/1227541844323110.xml&coll=7 (accessed April 30, 

2009).

13 Peter Schworm “Space heater eyed as cause in Lawrence fire,” www.boston.com, December 26, 2008. 

http://www.boston.com/news/local/breaking_news/2008/12/space_heater_ey.html (accessed April 30, 2009).

14 Heating is defined by the equipment used to heat a residential building. Incident Types 113, 115, 117, and 118 were 

excluded because by definition these Incident Types were not heating fires.

15 The USFA cause hierarchy is designed for structure fires. Buildings are a subset of structures. The cause hierarchy can be 

found at: http://www.usfa.dhs.gov/fireservice/nfirs/tools/fire_cause_category_matrix.shtm.