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Does Heat Kill Fleas? Vet Approved Facts, Risks & FAQ

Jeff Weishaupt

By Jeff Weishaupt

Dog fleas up close

Vet approved

Dr. Karyn Kanowski Photo

Reviewed & Fact-Checked By

Dr. Karyn Kanowski

BVSc MRCVS (Veterinarian)

The information is current and up-to-date in accordance with the latest veterinarian research.

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Fleas are wingless insects with a cuticle covering containing bristles and spines called ctenidia. Adult fleas can range in size from 0.1 cm to 0.32 cm. They grow by feeding on the blood of birds and mammals (including humans and their pets).

According to the Centers for Disease Control and Prevention, there are over 2,500 flea species in the world,1 and more than 300 of them are found in the United States. Fortunately, only a few of these types affect our health.

However, even those few can infest your home and pets, transmitting diseases and causing itchy bites. Heat is one way to kill fleas, but read on to find out what exactly is involved in ridding these pests from your home.

Can Heat Kill Fleas?

The short answer is yes. Heat kills fleas, but the degree of its effect on fleas depends on several factors, such as the flea’s life stage, duration of heat exposure, and temperature.

Fleas are ectothermic creatures,2 which means they use their environment to regulate internal body temperature. The ideal temperature for them to survive is 46°F (8°C) to 95°F (35°C), but fleas tend to be most active in temperatures ranging from 65°F (18°C) to 80°F (27°C).

Temperatures exceeding 95°F (35°C) for extended periods of time will kill most fleas and their larvae. Flea eggs tend to be more resilient, needing temperatures a few degrees hotter for longer periods for them to be destroyed.

The 3 Ways to Use Heat to Kill Fleas

1. Washing and Drying

If you have found fleas on your pet, there’s a good chance they’ve also invaded their toys and bedding. The best approach in this regard is to wash the items at a high temperature. But washing at high heat may not always be enough. You should supplement this by drying these items at a high heat too.

2. Steam Cleaning

If you have a steamer, you can also use it to kill fleas. The heat of the steam should be sufficient to kill the adult fleas and their eggs in your carpets, rugs, and furniture.

3. Hot Box

A hot box is a device that kills fleas and their eggs on items like clothing, bedding, and toys. All you have to do is keep the item in the hot box and the heat created by the device will kill any fleas infesting these items. Since the device is programmed to produce just the right amount of heat, it will not damage the clothing or toys.

woman doing laundry
Image Credit: Pixel-Shot, Shutterstock

How Long Does Heat Take to Kill Fleas?

The time it takes for heat to kill fleas in your home will depend on the heat application method and temperature you’re using. For instance, if you start a clothes dryer cycle for 30 minutes, it will kill fleas in all life stages, including adult fleas, larvae, and eggs. Likewise, steam cleaning at 140°F for over 10 minutes will kill fleas.

In most cases, exposing fleas to heat, such as keeping the infested item in the sun or using a hair dryer on it, won’t be sufficient to kill them. You must sustain the heat at a high enough temperature for a particular amount of time to ensure proper and complete eradication.

Can You Use Heat to Kill Fleas on Your Pet?

Let’s say you’ve confirmed the presence of fleas in your dog’s coat. Should you apply heat with a hair dryer to your pet’s body for half an hour? That’s a no-no, considering it will be uncomfortable for your pet and might even cause skin burns.

Laundry hanging from a clothesline
Image Credit: wilhei, Pixabay

The 3 Vet-Approve Methods of Removing Fleas from Your Pets

Vets recommend several ways to get rid of fleas if they’ve infested your pets. Here are some methods:

1. Spot-on or Oral Treatments

There is a huge array of chemical options for eliminating or preventing fleas on your pets; the safest and most reliable being those you get from your vet. The most important consideration when using these treatments is to read dosing instructions carefully and always follow veterinary advice. Most good products will kill not only adult fleas, but the eggs and larvae as well.

2. Give Your Pet a Bath

Not just an ordinary bath. You’ll have to use flea shampoo to clean your pet’s coat and hair. The effectiveness of a flea shampoo depends on its active ingredients. Some ingredients, such as peppermint, rosemary, and thyme oil, are plant-based. They might only work on mild cases of flea infestations.

To effectively kill fleas, you’ll need shampoos with chemical ingredients, such as type 1 pyrethroid insecticide for severe cases. Whichever shampoo you use, make sure its ingredients are EPA-approved. Be aware that when it comes to flea shampoos, the more effective the treatment, the higher the chance of causing a reaction. It is also worth noting that shampoos will only kill adult fleas, leaving larvae and eggs behind.

3. Use a Flea Comb

Since you cannot use heat on your pet, removing fleas manually using a fine-tooth flea comb is the other viable option. As mentioned earlier, fleas are pretty tiny. So, it’s hard to catch them with a regular comb.

Instead, you should get a comb specifically made for removing fleas. Make a mixture of dish soap and water. Now, dip the comb in this mixture and move it through your pet’s hair or coat.

Flea combs can also remove flea eggs from your pet’s fur. When moving the comb through your pet’s tail and neck, take extra care since this is where fleas often feed.

When you get fleas on the comb, do not try crushing them since their thick cuticle provides protection. You might think the flea is dead, but it will jump quickly as soon as you let it go.

Instead, dip the comb with fleas in the dish soap mixture so that it drowns them.

flea combing a tabby cat
Image Credit: Simone Hogan, Shutterstock


Do Fleas Die in the Dryer?

A hot dryer cycle can kill fleas in your clothes and other washable items. However, the cycle should be long enough—at least 30 minutes.

How Do You Know When Fleas Are Dying?

Fleas are usually very fast and are hard to catch. But if you’ve applied any form of heat treatment and notice them moving slowly, it’s a sign the treatment is working.

Does Sunlight Kill Fleas?

Sunlight might kill adult fleas if the daytime temperature is high enough. However, it does not kill larvae or flea eggs since they are more resilient to high temperatures.

How to Choose a Flea Shampoo for My Dog?

It’s best to consult a vet before using a flea shampoo to wash your pet, especially if your pet is nursing, pregnant, very old, or very young. You should also check if the ingredients in the shampoo are EPA-approved. Do not use dog and cat shampoos interchangeably, and always follow the instructions on the shampoo.

flea in animal fur
Image Credit: Vera Larina, Shutterstock


Prolonged exposure to temperatures over 95°F (35°C) kills fleas since they cannot withstand the heat. This can be useful when treating items like bedding and toys, but not for treating your pets themselves as it would be unsafe and inhumane to expose them to high temperatures for a long enough time to kill fleas.

Combining heating methods with effective flea treatments for your pets can be an effective way to tackle a flea infestation, but heat alone will not eliminate the problem. Always consult your vet for more information on the most effective way to safely deal with fleas.

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Featured Image Credit: photowind, Shutterstock

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