People often ask which bed bug treatment is best. The honest answer is that it depends on the home, the level of infestation and the people living there. Heat and insecticide are the two main routes, and many plans use both.
This post explains how each route works, what the evidence says, and how to weigh cost and disruption. It does not claim that one route always wins. It aims to help you ask better questions of anyone who quotes for the work.
How controlled heat works
Bed bugs and their eggs die when they sit at a high enough temperature for long enough. Heat treatment aims to bring a whole room, or a whole item, up to that temperature and hold it there. The method is not new, but modern equipment lets technicians monitor temperatures in many spots at once.
A 2026 laboratory study in Veterinary Medicine International tested a range of temperatures and exposure times. It found 100% mortality of bed bugs and their eggs at 45C with a 60-minute exposure. For cracked wood and mattress surfaces, the same study identified 75C for 30 minutes. In other words, the target is not the room air alone. Heat has to reach the places where the bugs actually hide.
This is why home methods are risky. A hair dryer or a space heater will not hold a safe, even temperature through a mattress seam or a wall void. As a result, a partial burst of heat can drive bugs into new rooms.
How insecticide treatment works
Insecticide treatment uses sprays, dusts or aerosols on the places where bed bugs hide and walk. Some products kill on contact. Others leave a dry residue that kills bugs as they cross it later.
The appeal is that a residue can keep working between visits. Moreover, a skilled technician can target cracks and crevices that are hard to reach. The weakness is resistance, which is covered below.
Insecticide plans normally need more than one visit. For example, eggs that survive the first treatment hatch afterwards, so a follow-up is needed to catch the new nymphs. Our post on how long bed bug treatment takes sets out a realistic timeline.
What the resistance evidence says
Resistance is the main reason insecticide alone can fail. The NHS says it is very difficult to get rid of bed bugs yourself because they can be hard to find and may be resistant to some insecticides. That is a plain warning for anyone planning a spray-can fix.
The research backs this up. A 2017 review in Parasites & Vectors says the worldwide resurgence of bed bugs is believed to be largely due to insecticide resistance. It describes thicker cuticles that slow the chemical down, enzymes that break it down, and gene mutations that make the target site less sensitive.
An earlier review in Medical and Veterinary Entomology found that the pyrethroid group had been the mainstay of bed bug control for decades. It reported that control failures were rising as tolerance grew. A 2023 review in the Annual Review of Entomology reached a similar view, adding that travel and poor pest management also helped the spread.
Therefore a good insecticide plan should not rely on one product used again and again. Ask what the technician will do if bugs are still present after the first follow-up.
Cost, disruption and fit
Heat tends to finish the active work in a single, long visit. However, it asks more of you on the day. You may need to move heat-sensitive items out, such as candles, aerosols and some electronics, and leave the home for several hours.
Insecticide work involves less on the day, but it asks for more preparation and more visits. You may need to strip beds, empty drawers and move furniture away from walls before each one. Our guide to preparing for treatment lists the steps, and they apply to both routes.
Cost depends on the size of the home, the level of infestation and the number of visits. Our guide to bed bug treatment costs explains what a fair written quote should include. Compare the whole scope, not only the headline figure.
When each route tends to fit
Heat often suits a single-household flat or house where you can clear the space and leave for the day. It is also useful when you want to limit chemical use, for example in a home with young children or someone who is pregnant. Even so, it works best when combined with careful inspection afterwards.
Insecticide tends to suit homes where heat is hard to apply. Examples include crowded rooms, shared buildings where neighbours will not co-operate, and places with fragile or heat-sensitive contents. In a flat, treating one home may also push bugs next door, so shared buildings need a joined-up plan.
Many plans therefore mix the two. A technician might heat a bedroom and treat the surrounding cracks and skirting. Similarly, a mattress may be steamed or heated while the room gets a residual treatment.
Heat helps even when it is not the main tool
Research suggests that moderate warmth can weaken a population. A 2018 study in PLoS ONE exposed bed bugs to 34, 36 or 38C for two or three weeks. It found fewer survivors, fewer eggs and weaker offspring. The authors said this is inadequate as a single tool for eradication, but may help as part of an integrated plan.
That finding does not mean you can turn up the heating and wait. It shows why professional plans combine methods rather than lean on one.
Questions to ask before you agree
Whichever route you pick, a clear plan matters more than the label. Ask the following before you book.
- What is the full scope, including every visit and follow-up?
- How will you check the result, and what happens if bugs remain?
- What do I need to remove, wash or move beforehand?
- How will you protect neighbouring homes in a shared building?
Local differences also matter. Flat dwellers can start with bed bug guidance for Camden and what Newham residents should know, because shared walls shape the plan. Meanwhile, the Barnet area guide, advice for Greenwich homes, the Kingston upon Thames local guide and help for Harrow households help if you live in a house, where a whole-home plan may be easier.
Before you spend anything, read how to choose between council and private bed bug treatment in London. Then check second-hand furniture before it enters your home, as covered in our guide to second-hand furniture and bed bugs in London. If you need urgent help, start with our urgent bed bug help guide.
Common questions
Is heat treatment always better than insecticide?
No. Each route has strengths and limits. Heat can reach hidden bugs without chemicals, but it suits some homes better than others. Insecticide can leave a residue that keeps working, but resistance means it is not a safe bet on its own.
Can bed bugs become resistant to insecticide?
Yes. A 2017 review in Parasites & Vectors describes several resistance mechanisms in bed bugs, including thicker cuticles and enzymes that break chemicals down. The NHS also warns that bed bugs may be resistant to some insecticides.
Can I heat my home or a room myself?
Home methods are risky and unreliable. Research on heat uses controlled equipment and monitored temperatures. Heaters, ovens and hair dryers can start fires, damage belongings and push bugs into other rooms.
Which route costs less?
It depends on the size of the home, the level of infestation and how many visits are needed. Ask for a written scope that lists every visit and follow-up. Our cost guide explains what to compare.