Cockroaches are known to be the hardiest creatures on Earth. Many studies focus on their survivability, which is impressive by any standard in the animal kingdom. They can even adapt to modern pesticides, but cockroaches are not invincible to high temperatures.
Cockroaches die if they are exposed to extreme heat. Although they prefer warmer climates, temperatures above 120 degrees Fahrenheit will kill them. Their hard exoskeleton is designed to protect them, but it falls within an hour if exposed to 131 degrees Fahrenheit. That’s because roaches are cold-blooded creatures, unable to control their own internal temperature. They are forced to absorb the surrounding temperatures, which, at high ranges, will bake them.
You can use heat from your dryer to speed up the effects of roach bait. You can also dispose of cockroaches by capturing and exposing them to fire. Even exposing roaches to temperatures just outside their preferred range can dramatically shorten their lifespans.
Are Cockroaches Heat Resistant?
Cockroaches are not heat resistant. In fact, they require their environment to be between specific temperatures to thrive. That’s because they are cold-blooded insects. Unlike warm-blooded creatures, roaches are unable to regulate their own body temperature.
Even still, roaches can withstand heat a lot better than humans can. Most species that infest everyday homes originate from hot climates, such as the Middle East and Africa. Their bodies are designed to withstand a certain degree of heat, with an ideal range of 70-90 degrees Fahrenheit. Even if temperatures climb up to 110 or just below 120, they will be fine.
This is made possible due to their exoskeleton. Cockroaches have a hard exterior that protects their organs and muscles from external harm. That includes environmental factors like temperature.
Roaches use this shell to absorb moisture from the air and breathe. However, it can also be closed up to protect their guts. While a person can be harmed by sunburn, a roach cannot. It can hold its breath to prevent hot air from drying out its organs for short periods of time. The design of its shell also keeps the roach from losing moisture to survive harsh conditions.
Eventually, though, a roach will succumb to extreme heat. They are not completely heat resistant and can die from temperature spikes.
Why Do Roaches Die From Heat?
Cold-blooded creatures are unable to control their body temperature because they lack brown fat. This is the kind of fat that warm-blooded animals directly convert into heat. Instead, ectothermic animals regulate their body temperature through external means. This includes:
- Bathing in the sun
- Moving to warm places during the winter
There are advantages to being cold-blooded. Roaches can instead devote energy to things other than building heat, such as:
- Conserving fat
That explains why cockroaches have such a prolific reproduction cycle. It also helps them go for long periods without eating. It does come at a cost, though. Roaches are vulnerable when the temperatures around them change.
If mammals are at risk of overheating, they can lower their body temperature. This is made possible through certain metabolic functions, such as sweating and salivating. It allows mammals to survive in less-than-ideal environments. They need the energy to keep those metabolic functions active.
However, cold-blooded insects like roaches have no way of cooling off. If they are at risk of overheating, their only option is to flee the area or find cold spots. If the climate itself is hot, or you’ve trapped a roach in a hot car, that becomes impossible. Even with a large amount of food and water at their disposal, they’ll still die.
At What Temperature Will Cockroaches Die?
Cockroaches are in danger of fatal heat exposure at 120 degrees Fahrenheit. At this point, the roaches will die in 2 to 7 hours.
This gives them time to vacate the area. If a roach is sickly or injured, it may succumb to the heat more quickly. The hotter this temperature gets, the less time it takes for any cockroach to die.
Once the temperatures climb up to 125-130 degrees Fahrenheit, roaches will have little time to survive. According to the Journal of Insect Physiology, a cockroach’s nervous system reacts directly to temperature. If the surroundings become cold, it can activate a type of coma that allows it to weather the change for several days. However, roaches possess no such defense against heat.
Instead, a cockroach will find its exoskeleton turning against it at 131 degrees Fahrenheit. The thick keratin shell will no longer insulate its organs. The heat will penetrate and begin drying out its vital body parts. The roach will dry out, lose its ability to breathe, and die within 1 hour.
Do Roaches Get Weaker In The Heat?
Even if a cockroach manages to escape before the heat is lethal, it will be affected long-term. For example, according to the University of Minnesota, a mother cockroach will not transmit fat-body intracellular symbiotes to her eggs. Exposure to heat treatment effectively removes this ability. This leaves the next generation weaker, lacking an important collection of microorganisms that help make roaches durable.
Interestingly enough, that doesn’t impact all of a cockroach’s microorganisms. According to The Society for Applied Microbiology, the gut bacteria of the Madagascar and Dubia roaches were able to withstand temperatures of 95 degrees Celsius in the proper conditions. While that won’t help the roach that contains those microorganisms, it proves that they are durable even on a microscopic level.
In the macro-sense, roaches live shorter lifespans if consistently exposed to temperatures above their ideal range. This will not kill them immediately, but it may shave numerous weeks off their life expectancy. For example, here is the preferred range for the most common household roaches:
|Type of Cockroach||Preferred Temperature|
|American Cockroach||68 to 84 °F|
|German Cockroach||59 to 95 °F|
|Oriental Cockroach||68 to 86 °F|
Even the colder-range-loving American cockroach will be able to handle temperatures of 100 degrees Fahrenheit. It may grow, lay eggs, and infest homes like normal. However, instead of reaching its possible lifespan of 2 years, it may only survive for several months.
Nonetheless, that’s enough to keep the species alive. Cockroaches have been around for more than 300 million years. That means they were present when the Earth was at its hottest, such as during the Cretaceous period. By reproducing at such a rapid pace, they can keep lethal conditions from halting the species as a whole.
Killing Roaches with Heat
If you’re concerned about using toxic chemicals, then roaches can be killed with heat. Depending on your situation, it can be an effective pest control method for your home.
With that said, you should proceed with caution. Roaches are more tolerant of heat than:
- Human beings
- Certain household items
- Electronic parts
Professional Heat Treatment for Cockroaches
Exterminators sometimes offer heat treatment as a way to kill off roach infestations. This works effectively against adult roaches and eggs. The main treatment will involve:
- Targeting one area of the house at a time
- Removing items that could be damaged by the heat treatment
- Sealing the area to insulate rooms and prevent roaches from escaping
- Raising the temperature in a controlled way with fans, pipes, and boilers
Thermometers and infrared cameras are used to detect cold zones throughout a room. In response, the fans are directed to blow hot air towards those areas. This ensures there isn’t a single spot where cockroaches can hide.
While this can be effective, it doesn’t suit every home or every infestation. For example, some homes cannot withstand high temperature ranges. You could dry out the plaster in your walls and cause fissures to develop.
More importantly, it’s unwise to use house-wide heat treatment against roaches by yourself. A lack of experience or incorrect tools may result in:
- Cold spots being left behind, allowing them to evade the treatment
- Temperatures not being raised to the correct range, doing damage, or leaving the bugs unaffected
- Damage caused to your home, furniture, and electronics
- Injury or other harm being caused to you or others
DIY Heat Treatment for Cockroaches
For home purposes, the best way to use heat is to drive roaches out. If you place a space heater near a suspected nest, the cockroaches will be compelled to migrate to other parts of the house.
As they leave to cool off, they may be driven into roach traps, bait, and pesticide measures. This can make traditional pest management more effective.
Temperature To Kill Cockroaches
If you really want to use heat treatment against roaches, there are certain situations where it’s safe. For example, if your climate normally reaches temperatures above 100 degrees Fahrenheit, you can use this to your advantage. This allows you to treat roaches in your:
As discussed, roaches will die when exposed to temperatures over 120 degrees Fahrenheit. If these areas are well-insulated and exposed to outside heat, they may achieve that range naturally. You need only exacerbate the heat by turning off any fans or coolers. If it’s well insulated, open the doors so hot air can get in.
For your car, remove all items that may be damaged by heat. Place it in the sun, but cover the windows so that light does not directly bake into your dashboard. This may harm the plastic, as well as sun-fade other parts of your interior. Allow it to sit in the sun for the entire day or several days if you’re able. To be extra sure, place a thermometer inside the car, so you can check when it’s reached the correct temperature.
You can exacerbate the heat of all areas with the use of space heaters. These are fans that blow out hot air and raise the temperature of a room. However, while many portable space heaters can go up to 150 degrees Fahrenheit, you shouldn’t leave them on for several hours at this temperature. Doing so may be a safety hazard. Instead, use it to help raise the temperatures short-term.
Aside from using the weather, you can also trap cockroaches using bait. Once captured, they can be disposed of using heat. Place them in a metal container and place them in an open fire.
Does Dryer Heat Kill Roaches?
The heat settings on an average dryer will vary between 120-135 degrees Fahrenheit. However, some brands possess a higher range that’s capable of attaining 176 degrees Fahrenheit. Because of this, cockroaches can die during a tumble in your drying machine.
If you have clothing infested by roaches, this is a clear way to destroy them. However, it’s recommended to shake any roaches out before sanitizing your clothes. Grown roaches will likely break into pieces or come out in chunks across your clothing. Not only is this disgusting, but also unhygienic.
If you want to use a dryer to kill roaches, you can use it indirectly. Dryers produce a mild amount of heat on their exterior. It’s not enough to be scalding, but it is warm. If you place cockroach bait under or behind the dryer, roaches will be drawn to this location. As they feed, they will overheat.
This will make the roaches extremely dizzy for a few hours. At this point, you can destroy them immediately, should you be unwilling to wait on the bait traps.
Even if you do not capture them, any poison they ingest will activate more quickly. For example, in normal conditions, boric acid takes up to a week to kill roaches. If exposed to heat, they will die much sooner. Once overheated, roaches will struggle to break down the toxic substances at the same rate.
Cockroaches die in the heat. Even cockroaches can’t tolerate high ranges for several hours. When it goes over 131 degrees Fahrenheit, roaches will die off very quickly.