[Tech Talk] Avoiding Heat Chamber Failures

As resistance to multiple pesticides increases in bed bug populations, there have been a number of pest management companies that have switched their treatments to heat chamber treatments. Although fumigation is the most reliable way to completely eliminate a bed bug problem with a single treatment, not all companies have the resources to establish fumigation as a treatment option. Heat chambers offer an alternative that is highly effective with a relatively low start-up cost. Heat chambers can be very effective at killing all stages of bed bugs and, in some cases, can be better suited than chemical treatments. However, heat chamber treatments can fail if the thermal death point is not determined correctly or air penetration is not achieved.

A thermal death point is determined by the temperature and exposure duration. Bed bugs and their eggs have a thermal death point of 118°F for at least 90 minutes. Although bed bugs can be killed at 113°F, you will leave your client at risk for the eggs hatching if you do not get the treatment area hot enough. If these eggs hatch after a heat treatment with no pesticide residual, they will have the opportunity to re-infest the area. Ensuring that the treatment area reaches and maintains the proper treatment temperature is of the utmost importance.

Even if you are above the proper temperature for your treatment area, there is still a chance that bed bugs can survive the treatment if they are in pockets of protected air. Items that are stacked with no gaps between them to allow for proper airflow can provide harborage points for bed bugs. Creating an air gap allows the bed bugs to be exposed to the heated air and reduces areas that can protect the bed bugs from the heat treatment. Insulated items and areas that are covered with dust covers, such as headboards, under chairs and box springs, bring risks as well. Proper access must be given to allow for the heat to penetrate these areas or a failure can occur. The areas where bed bugs could be protected are where you must monitor as the treatment is occurring. Once the proper temperature has been reached in these hard-to-penetrate areas, you can start your clock for the treatment duration. If you ignore these areas, you increase your risk for bed bugs surviving your treatment.

Only after you have verified that the chamber is elevated to the proper temperature in all areas can you start your treatment timer. Monitoring in these areas is pivotal for treatment success. If you do not have your temperature probes in the correct space, you run the risk of extra time on site or a treatment failure — and you will have to retreat the items.

Ensuring that a terminal temperature is reached and maintained in the chamber is essential. However, you have to ensure the temperature is being reached in the protected environments. If you do not find these pockets where the thermal death point cannot be reached, then you will have an increased risk of a treatment failing. By concentrating your monitoring in these low-temperature zones, you will help reduce your callbacks and increase the efficiency of your treatments.
 

David Moore received his master’s degree in entomology from Virginia Tech specializing in bed bugs. He serves as the manager of technical services for Dodson Bros. Exterminating.

Copesan is an alliance of pest management companies with locations throughout North America. To learn more, visit www.copesan.com.