Bed Bug Basics and Identification: Signs, Science and the Heat Treatment That Works
Bed bugs are experts at hiding, spreading quietly and frustrating well-meaning DIY efforts. If you’ve noticed bites, dark spotting on sheets, or tiny apple-seed sized insects along seams and frame joints, you’re not alone — and you’re not doing anything “wrong”. ThermoPest specialises in whole-room heat, the method that solves what sprays and gadgets often cannot.
This guide explains what truly identifies a bed bug problem, the science behind effective control, and why targeted heat treatment is the gold standard. We’ll also show you safe steps you can take now and how to avoid common pitfalls that make infestations linger.
When you’re ready to act, see our bed bug heat treatment and learn exactly what we do during our bed bug heat treatment process.
What people believe vs reality
- Belief: “If I can’t see bugs in the day, they’re gone.” Reality: Bed bugs are nocturnal and hide deep in cracks, under fabric staples, inside bed frames and skirting gaps.
- Belief: “A quick spray will sort it.” Reality: Resistance to common insecticides is widespread and eggs are notably resilient; sprays often move bugs into new rooms.
- Belief: “Throwing the bed out fixes it.” Reality: Bugs often live in bedside furniture, sockets, headboards and flooring; removing a mattress rarely removes the source.
- Belief: “A few bites means it’s minor.” Reality: Bite reactions vary between people; you can have a sizeable infestation with minimal skin response.
Science-backed facts
UK bed bug issues are typically caused by Cimex lectularius, a human-preferring species that feeds every few days and shelters close to where we rest. Eggs hatch in around 7–10 days at room temperature and nymphs develop through five stages, feeding between each stage. Adults and nymphs can survive weeks without feeding, so short absences or temporary spraying rarely eliminate them.
Lethality is driven by time and temperature. Adults and nymphs die quickly above the high 40s °C, while eggs are tougher and require higher temperatures and sustained exposure. See the detailed science behind what temperature kills bed bugs and why hold-times matter.
Common mistakes that prolong infestations
- Spot-spraying or fogging rooms, which scatters bugs and misses eggs hidden deep inside furniture.
- Moving beds and soft furnishings around the home, unintentionally spreading infestations to new rooms.
- Piling laundry without sealing bags first, allowing bugs to drop off en route to the washing machine.
- Relying on brief, localised steam or hairdryers; heat must penetrate deeply and stay lethal long enough to kill eggs.
- Declaring victory too soon; without proper monitoring, a few survivors can rebuild.
Practical steps you can do safely
- Launder bed linens and clothing on a hot cycle (60°C wash where fabric care labels allow) and tumble dry on high heat for at least 30 minutes after items are fully dry.
- Bag items before moving them through the property; load directly from the bag into the machine and re-bag clean items.
- Vacuum slowly along mattress seams, headboard fixings and bed joints using a crevice tool; dispose of the vacuum bag immediately in a sealed bag.
- Use tight-weave mattress and base encasements to trap existing bugs and deny harbourage.
- Minimise room-to-room movement of bedding and furniture until treatment; avoid over-the-counter sprays that can drive bugs into new harbourages.
- If you’ve booked professional heat, read preparing your home for treatment to maximise success.
Why heat treatment is the superior solution
Modern bed bug control is about physics and proof. Whole-room heat doesn’t rely on insecticides, so resistance isn’t an obstacle, and the method reaches where sprays and dusts cannot.
Eliminating cold spots
Bed bugs survive in tiny “cold spots” — behind skirting, inside bed frames, under carpet edges and inside sockets. Professional systems create uniform convection and use targeted agitation so thermal energy penetrates these protected voids, removing safe refuges.
Sustained lethal temperature
Success isn’t a quick blast. We bring the entire treatment zone to lethal temperatures and maintain them long enough to kill eggs as well as mobile stages. Typical programmes hold core harbourages above lethal thresholds for 60–120 minutes, verified by sensors.
Sensors and monitoring
Heat without measurement is guesswork. ThermoPest deploys multiple wired and wireless probes inside mattresses, drawers and structural gaps to data-log temperatures in real time. Technicians adjust airflow and positioning to ensure every probe clears the lethal window and stays there.
All life stages killed
When cold spots are eliminated and hold-times are verified, heat treatment neutralises eggs, nymphs and adults in one operation, drastically reducing the chance of survivors. Aftercare is essential to detect any re-introduction; here’s how to monitor your property after treatment.
ThermoPest expertise
ThermoPest is dedicated to evidence-led heat control. Our technicians plan airflows, instrument the room, and follow a documented protocol so outcomes aren’t left to chance — review our bed bug heat treatment process to see how we verify every stage. For homes, flats and HMOs we adapt to construction and contents; for businesses, we deliver commercial heat treatment for hotels and landlords to minimise downtime and guest impact.
If you’re still researching, our guide to bed bug heat treatment explains the method, prep and aftercare in one place. For the technical thresholds and timings, refer again to what temperature kills bed bugs.
FAQ’S
Question: What are the first reliable signs of bed bugs?
Answer: Look for dark faecal spotting (tiny ink-like dots) on sheets, mattress seams and bed frames, plus cast skins and live bugs in joints and screw holes. Bites can be a clue but aren’t diagnostic, as reactions vary widely. Use a torch and a credit card edge to probe seams, headboard fixings and slats where eggs and nymphs hide. A quick vacuum of finds into a clear bag helps you confirm evidence; in professional practice we always rely on physical signs, not bites alone.
Question: Will washing and drying kill bed bugs and eggs?
Answer: Yes, if done hot enough for long enough. A 60°C wash (where care labels allow) and a full high-heat tumble dry for at least 30 minutes after items are dry will kill mobile stages and eggs; cooler cycles may leave survivors. The risk is spreading bugs while transporting laundry. Bag items at the source and load directly into the machine; in professional practice we pair this with room heat to cover items that can’t be laundered.
Question: Why do infestations persist after spraying or fogging?
Answer: Many bed bug populations show resistance to common insecticides, and eggs are naturally more tolerant. Sprays and fogs often miss deep harbourages and can drive bugs into wall voids or new rooms, creating ‘cold spot’ refuges that survive treatment. DIY overuse can also reduce detection accuracy by scattering evidence. If you’ve already sprayed, pause further chemicals and focus on inspection and preparation; in professional practice we use whole-room heat to remove resistance as a variable.
Question: What’s the difference between re-introduction and re-infestation?
Answer: Re-introduction is when new bugs arrive after a successful treatment (for example via luggage, used furniture or visiting guests). Re-infestation suggests the original population wasn’t fully eliminated, often due to untreated cold spots or insufficient hold-time at lethal temperatures. The distinction matters for aftercare and monitoring plans. Use interceptors on bed legs and inspect weekly for four weeks; in professional practice we combine monitors with follow-up checks to confirm clearance.
Question: Is DIY heat or steam enough to clear bed bugs?
Answer: Steam can kill on contact, but only if the nozzle delivers sustained heat deeply into seams and joints; many household units struggle to maintain lethal temperatures in hidden spaces. Space heaters or hairdryers are unsafe and create uneven heating that leaves cold spots and surviving eggs. If you do steam, move slowly (about 2–3 cm per second) and target seams and cracks. Treat this as a reduction step, not a cure; in professional practice we use instrumented room heat to verify every harbourage reaches lethality.