Unused car at 21 °C: most dead after about 144 days without a meal (Johnson 1941; Polanco et al. 2011). Full sun: cabin air rises about 16–27 °C (28–49 °F) in an hour (McLaren et al. 2005) — lethal in the open, not reliably in seams. Cold: most survive 3 weeks at 0 °C (Rukke et al. 2017). Clean: vacuum seams and buckles, steam seats, re-check in 1–2 weeks (NPMA).
How long can bed bugs live in a car?
A car is a hiding place with only occasional meals. If nobody uses it, bed bugs inside it are in the same position as bugs in an empty room: they wait, and they slowly starve. At a mild 21 °C (70 °F) that takes about 144 days for most bugs of the hardiest stage, and about 463 days when it's cool at 13 °C (Johnson 1941; Polanco, Miller & Brewster 2011). A car that's driven every day is different: a bug in a seat seam can feed on the driver or passengers and the clock restarts.
So how long can bed bugs live in a car? Weeks to months, depending on the temperature inside it and whether anyone sits in it. The checker above uses the cabin temperature with the same survival and kill-time figures as our no-host calculator and temperature calculator.
Can bed bugs live in your car?
Can bed bugs live in your car? Yes, they can survive there, though cars aren't where they breed best. Bed bugs are "efficient hitchhikers" that travel on "luggage, clothing, beds, furniture, and belongings" (University of Kentucky), and a car carries all of those. The National Pest Management Association warns that buses, trains and taxis are at risk because "riders may transport them in clothing, luggage, carry-ons, or other personal possessions". A car used to move furniture, or to collect bags from an infested home, is the most likely to pick some up.
Will a hot car kill bed bugs?
Will a hot car kill bed bugs? Sometimes, in some parts of the car, for some of the bugs. Cars in the sun do get hot enough to kill bed bugs in the open air of the cabin. In a study of a dark sedan parked in full sun on clear days of 22–36 °C (72–96 °F), the air inside rose by an average of 41 °F (23 °C), from 28 to 49 °F (16–27 °C), within an hour, with 80% of the rise in the first 30 minutes; even on a 72 °F day it reached 117 °F (47 °C) (McLaren, Null & Quinn 2005). Earlier work they quote measured 51–67 °C inside cars within 15 minutes on a 36.8 °C day.
| Outside temperature | Cabin air after 1 hour | Kill time, cooler end | Kill time, hotter end |
|---|---|---|---|
| 22.2 °C (72 °F) | 37.8–49.4 °C (100–120.9 °F) | not lethal | 72 minutes |
| 25 °C (77 °F) | 40.6–52.2 °C (105.1–126 °F) | not lethal | on reaching it |
| 30 °C (86 °F) | 45.6–57.2 °C (114.1–135 °F) | 7.1 hours | on reaching it |
| 35.6 °C (96.1 °F) | 51.2–62.8 °C (124.2–145 °F) | on reaching it | on reaching it |
Those kill times — from the same data as our temperature calculator, for adults and eggs together — look encouraging, but three things make a hot car an unreliable treatment:
- The heat doesn't last. A parked car is hot for some daylight hours, then cools overnight. Eggs need about 7.1 hours at 45 °C (Kells & Goblirsch 2011), and every hiding place has to stay that hot for the whole time.
- Hiding places are cooler. The study measured air in the shade above the rear seat. Bugs hide in seat seams, under carpets and in the boot, which warm up more slowly — just as the underside of a sun-baked mattress stayed at 36.5 °C while the top passed 80 °C (Doggett and colleagues, reported by Loudon 2017).
- Bugs move. As things heat up, bed bugs can retreat deeper into cooler spots (Loudon 2017).
Can bed bugs live in a hot car?
Can bed bugs live in a hot car? The ones in hot, exposed spots won't; the ones deep in upholstery may. That's why the checker shows two things in sunny weather: the kill time at the cabin temperature, and how long hidden bugs could last if the heat never reaches them. Using the car as an oven for items is more promising than using it to clean the car itself: Kentucky says items wrapped in plastic can be left "inside a closed vehicle parked in the sun", packed loosely in black bags and raised off the floor, and that "a hot car can often do the trick in summer" for suitcases — as long as a thermometer shows at least 120 °F (49 °C) wherever bugs may be. The EPA agrees it can work, "but success depends on your climate and other factors". Never leave children or animals in a hot car.
Bed bugs in a cold car
Can bed bugs survive in a cold car? For a long time, unless it gets very cold for a long time. Cold slows bed bugs right down — they stop moving on their own below about 9.5 °C (Johnson 1941) — but it doesn't kill them quickly. Most survived three weeks at 0 °C in a 2017 study; at −10 °C it took about 3 weeks to kill them all (Rukke, Hage & Aak), and below −20 °C about 48 hours (Olson et al. 2013). We found no study measuring how cold a parked car's cabin and seats get compared with the air outside, so the checker asks you to measure it. Seat foam and carpet are insulated, so they will lag behind the outside air, and a sunny winter afternoon can warm the cabin above freezing. For freezing outdoors in general, see do bed bugs die in winter.
Where bed bugs hide in cars
Bed bugs hide in tight, dark cracks near where people sit. The NPMA's guidelines for public transport vehicles list the places to vacuum: "deep in the seams, creases, and crevices in upholstered seats, around luggage storage areas, and inside seatbelt buckle assemblies", and suggest steam or spot cold treatment in "seats, carpet edges, and in cracks and crevices". For a family car, that translates to:
- Bed bugs in car seats: seams, piping, the gap between seat back and cushion, and under the seats.
- Seatbelt buckles and slots where belts disappear into the seat.
- Carpet edges and floor mats, especially under the front seats.
- The boot (trunk) where bags and boxes sit, and its side pockets.
- Child seats, blankets, cushions and anything else soft left in the car.
Look for the usual signs: live bugs, pale shed skins, tiny pearl-white eggs and dark spots (EPA). A torch and an old credit card help.
How to get rid of bed bugs in a car
How to get rid of bed bugs in a car without pesticides comes down to removing, heating and checking. From NPMA, EPA, University of Minnesota and Kentucky guidance:
- Take everything out. Bag loose items in the car before carrying them indoors. Put fabric items, seat covers and blankets in a dryer for 30 minutes on high (University of Minnesota).
- Vacuum thoroughly. Work deep into seams, creases, crevices, buckles and carpet edges (NPMA). Afterwards, seal the vacuum bag "as tightly as possible and immediately throw it out in an outdoor trash container" (EPA).
- Steam the upholstery. The EPA says steam must be at least 130 °F (54 °C) "but should not have a forceful airflow, or it may cause bed bugs to scatter". The University of Minnesota recommends a steamer with at least a gallon capacity and a surface temperature of 160–180 °F (71–82 °C) right after the steam passes, checked with an infrared thermometer. Take care — steam burns.
- Treat smaller items with heat or cold. Wrap items in plastic and heat them in the parked car with a thermometer inside (Kentucky), or bag and freeze them; see our plastic bag timer for how long.
- Check again in one to two weeks. The NPMA advises re-inspecting vehicles 1–2 weeks after treatment; eggs that survived will have hatched by then at room temperature (Johnson 1941).
- Call a professional if bugs keep turning up. Professionals can heat-treat or fumigate a whole vehicle (NPMA). Don't use foggers or garden insecticides in a car.
And deal with the source: a car usually gets bed bugs from a home, a bag or a piece of furniture. If you find them in the car, check your bedroom too.
How this car calculator works
- Cabin temperature: if you enter a measured value, it is used. If not, and the car is in full sun on a 22.2–35.6 °C (72–96 °F) day, the cabin air is estimated as outside plus 15.6–27.2 °C after an hour (McLaren et al. 2005). For shade, night, cooler or hotter days there is no published figure we could use, so the checker asks you to measure.
- 40 °C and hotter: the heat kill time for adults and eggs (Kells & Goblirsch 2011; Mellanby 1935) at the cooler end of the cabin range — and, because cars cool down and seats stay cooler, how long hidden bugs could last without a meal at 28 °C, the warmest temperature the starvation studies cover.
- 7–40 °C: survival without a blood meal (Johnson 1941; Polanco et al. 2011), compared with the days unused: "still likely alive", "many dying" after the hardiest stage's average, "most dead" after the longest single bug recorded. Above 28 °C the 28 °C figure is an upper limit.
- Below 7 °C: the same status as our cold survival calculator for an unheated place (Johnson 1941; Rukke et al. 2017; Olson et al. 2013).
Anyone riding in the car gives the bugs a chance to feed, which resets the clock.
Frequently asked questions
How long can bed bugs live in a car?
If no one uses it, as long as they can without a blood meal: most are dead after about 144 days at 21 °C and about 463 days at 13 °C. A car in daily use can keep them fed.
Will a hot car kill bed bugs?
Not reliably. Cabin air in full sun can pass 45–50 °C within an hour (McLaren et al. 2005), but the heat doesn't last and seat seams stay cooler. Use it for bagged items with a thermometer, not as a car treatment.
How hot does a car get in the sun?
In one study, about 16–27 °C (28–49 °F) above the outside temperature after an hour on clear 22–36 °C days, with 80% of the rise in the first 30 minutes (McLaren et al. 2005).
Can bed bugs survive in a cold car?
Usually. Most survived 3 weeks at 0 °C; it takes about 3 weeks at −10 °C or 2 days below −20 °C to kill them all (Rukke et al. 2017; Olson et al. 2013).
Where do bed bugs hide in a car?
Deep in seat seams, creases and crevices, around luggage areas and inside seatbelt buckle assemblies, plus carpet edges (NPMA).
How do I get rid of bed bugs in my car without chemicals?
Remove and dryer-treat fabric items, vacuum seams and crevices, steam upholstery at 160–180 °F surface temperature, and re-check in 1–2 weeks (University of Minnesota; NPMA).
Can I use my car to heat-treat a suitcase?
Kentucky says a hot car can often do it in summer — pack items loosely in black bags and confirm at least 120 °F (49 °C) inside with a thermometer.
Can bed bugs live in car seats?
Yes. Seat seams and the gap between seat back and cushion are the main hiding places, like mattress seams in a bedroom.
Does cracking the windows change how hot a car gets?
No. In the McLaren study, cracked windows made no difference to the rate of heating or the final temperature.
These calculators give estimates from laboratory studies, for education. Real bed bugs vary with strain, insecticide resistance, humidity and how easily they reach a host. Bed bugs are not known to spread disease (CDC), but if bites trouble you, talk to a doctor or pharmacist. For an infestation, contact a licensed pest professional or your local extension service. We give no pesticide advice.