Heat Guns

Heat guns blow air hot enough to ignite wood, paper, insulation and dust, and they’re a common cause of burns and building fires during renovation work. They are used to strip paint, soften adhesives, bend plastic, shrink tubing and thaw things out. Used carelessly, a tool that looks like a hair dryer can start a fire that nobody notices until the wall is burning. Used carefully, it is a handy tool.

• Construction
• General Industry

How hot is a heat gun?

• Most heat guns put out air between about 120°F and 1,000°F or more. Many have two or three settings, and some have a digital temperature control. The high setting on many models is around 1,000°F to 1,200°F.
• Wood, paper and many plastics ignite or char at a few hundred degrees, which is well within a heat gun’s range. Dust, sawdust, insulation, paint and rags ignite even more easily.
• Unlike a flame, a heat gun has no glow to warn you. Heat can pass through a gap or crack and heat wood or insulation inside a wall that you can’t see. A smoldering fire can start and burn for hours before it shows.
• The metal nozzle stays hot for many minutes after you switch it off, long enough to burn skin or set something on fire.

Common uses and their risks

Using a heat gun safely

• Keep the nozzle moving and keep it pointed away from combustible materials, including hidden ones behind walls, under trim and inside cavities. Never hold it in one spot.
• Check the area first. Move or cover anything that can burn, such as drop cloths, paper, rags, sawdust, plastic sheeting and wood. Look behind and below the work for insulation, nests, dust and wiring.
• Use the lowest temperature that works, and test on a small spot. A lower setting often takes only slightly longer.
• Have a fire extinguisher nearby when stripping paint or working near wood, and know how to use it. See Fire Extinguishers (PASS).
• Rest the hot gun on its stand, nozzle up, away from anything flammable. Many heat guns have a flat rest or a hang loop. Don’t set a hot gun on a bench with the nozzle against paper or wood.
• Let it cool before you store it. Switch it to the cool setting for a minute to cool the element, then switch it off, and wait until the nozzle is cool to the touch.
• Wear heat-resistant gloves and safety glasses. A scraper can slip, and hot paint can spatter. See Eye & Face Protection and Hand Protection.
• Use GFCI protection and a proper cord, and keep the cord away from the nozzle. See GFCI and Extension Cords.
• Check after you finish. Look for smoke, a burning smell or scorched spots, and go back to check an hour or more later. Many employers require a fire watch for a time after heat work. See Hot Work Permits.

• Don’t touch the nozzle or point it at people.
• Don’t use it near flammable vapors, solvents or gas cylinders. Chemical strippers and heat don’t mix, and vapors can ignite. See Flammable Liquids.
• Don’t leave it running unattended, even for a moment, and don’t put it down on or in anything.
• Don’t block the air intake at the back, since the tool will overheat.
• Don’t use it as a hair dryer, or to start fires, warm yourself or dry clothing.
• Don’t use it in wet areas or near water, or with a damaged cord or housing. See Tagging Out Damaged Tools.

Heat guns and fire safety on the job

• Many employers and fire codes treat heat gun work near combustibles as hot work and require a permit, a fire watch and an extinguisher. Ask what your site requires. See Jobsite Fire Prevention.
• In occupied buildings, tell the people there, and shut off or protect smoke detectors only as the site rules allow, restoring them afterward. See Occupied Building Hot Work.
• If something ignites, switch off and unplug the gun, use an extinguisher on a small fire, and call 911 for anything you can’t put out at once. Check the wall or ceiling behind the work for hidden fire.

Fumes and dust

• Heating paint, varnish, adhesives and plastics gives off fumes and vapors that irritate the eyes, nose and lungs, and some are toxic. Work with good ventilation, such as open windows, fans moving air out, and take breaks outdoors. See Ventilation.
• Scraped residue can contain lead or other metals. Wear the right respirator when required, and clean up with a HEPA vacuum. See Respiratory Protection.
• Old flooring, tile and mastic may contain asbestos. Don’t heat or scrape suspect materials until they are tested. See Asbestos Laws Explained.

Safer ways to strip paint

• Test first. If the building was built before 1978, test for lead before disturbing paint, or assume it is present.
• Scraping and wet scraping with controls, chemical strippers (not methylene chloride, which is deadly in closed spaces), and infrared strippers are alternatives. Each has its own hazards. See Methylene Chloride & Paint Strippers.
• Never use open-flame torches or high-heat guns on lead paint.
• Contain the work area, cover floors, and clean up with a HEPA vacuum and wet wiping. Don’t dry sweep.
• Keep children and pregnant women out of the work area, and wash up before eating. See Lead & Asbestos in Older Homes.

Burns and first aid

• For a burn from the nozzle or hot air, cool the burn with cool running water for 10 to 20 minutes, remove rings and watches near it, and cover loosely with a clean dressing. See Burn First Aid.
• Get medical help for blisters larger than a coin, burns on the hands, face or joints, and any deep or white burn.

Inspection and care

• Check the cord, plug, switch, housing, nozzle and vents before each use. Take damaged tools out of service.
• Keep vents free of dust, and clean the intake screen.
• Use only attachments and nozzles made for your tool, and let them cool before changing them.
• Store the gun cool, clean and dry, with the cord loosely coiled.

Before you switch it on

• Combustibles removed or covered, and the area behind the work checked
• Lowest effective temperature chosen; paint tested for lead if built before 1978
• Extinguisher at hand; hot work permit and fire watch if required
• Ventilation set up; gloves, safety glasses and the right respirator on
• GFCI-protected cord; nozzle stand ready
• Plan to check the area again after work

Last updated: October 4, 2026