Editor's note: Included in the March PCT bed bug supplement was “Avoiding Hot Water” a feature reviewing what PMPs need to know about bed bug heat treatments and sprinkler systems. The following online extra includes additional best management practices for using heat.
Using sensors in the harborage areas is recommended to ensure lethal temperatures are reached. The surface of a mattress or cushion may reach lethal levels, for example, but the temperature on the inside or beneath the item may be considerably cooler. As a result, it is often necessary to raise ambient air temperature above bed bug-lethal levels.
Ambient air temperature should also be monitored. “Certainly heat is good at killing bed bugs, but a certain level of heat is also effective at peeling the wallpaper off of the wall and melting the television,” explained Jim Fredericks, NPMA technical director. “So it’s important to not only monitor insulated harborage areas, but also to monitor ambient air temperature” out of concern for your customer’s property.
Heat treatments “typically provide more flexibility for use in cluttered environments than traditional pesticide applications,” according to the BMPs. “When you get into a bed bug job oftentimes we find it difficult to treat, especially in multi-family housing with a cluttered environment,” said Fredericks. “If you’re going to do a ‘crack and crevice’ treatment with an insecticide the more items that are in the room, the more cracks and crevices are available for the bed bugs to hide. Heat, on the other hand, will find its way into those cracks and crevices, assuming that the clutter itself doesn’t impede the heat from reaching those bugs. It’s certainly a good control method and has some real use in some of these cluttered environments.”
Heat treatment is effective, but it also has its limitations. Airflow can effect whether heat can reach harborage areas. Heat loss within a room or building should be considered. If it is a poorly insulated room or building, it may take longer to reach and maintain the necessary temperature. Your geographic location and season also need to be considered. Using heat to treat bed bugs during a New England winter is certainly different from a job in south Florida during the summer.
The BMPs offers a reminder to only use the proper, professional equipment for heat treatments. It should be tested for use as an insect control device for whole room heat treatments. Equipment should be inspected before use to ensure it is in working order and there are no foreseeable fire hazards.
The reminder to only use proper equipment was added, in part, for the public. There have been cases where people used gas grills, portable kerosene heaters, or propane stoves to perform their own heat treatment. The potential is very real for injury to people and damage to property.
Hard lessons have been learned in the field. One anecdotal story reports that heat equipment was left outside unattended while preparing for a job and someone mistook it for a trash receptacle. “And when the equipment was turned on,” explained Fredericks, “it ejected flaming fire balls, which is a problem.”