Some pest control firms also employ commercial steamers or spot-freezing equipment to treat areas where bed bugs are found or suspected. Used correctly, they kill bugs and eggs on contact. Neither method, however, affords residual protection against bed bugs which may have been missed. Steaming and spot-freezing equipment also have limited ability to penetrate fabric, wood, and other materials where bed bugs often reside. 
If all other options have been exhausted, you may need to seek a professional PMP (Pest Management Professional). There are pesticides that are approved for professionals to use during a infestation. These pesticides, however, are not always effective, and typically not as effective as steam cleaning, excessive heat, or excessive cold. The exterminator may opt to treat the area with carbon dioxide.

Dusts have been used to ward off insects from grain storage for centuries, including plant ash, lime, dolomite, certain types of soil, and diatomaceous earth or Kieselguhr.[60] Of these, diatomaceous earth in particular has seen a revival as a nontoxic (when in amorphous form) residual pesticide for bed bug abatement. While diatomaceous earth performed poorly, silica gel may be effective.[61][62] 

* Typically used for control of wood-destroying organisms, true fumigation of structures is occasionally performed for bed bug control. Fumigating a structure involves “tenting” it, i.e., draping and sealing it with tarps so that the fumigant, a poisonous gas, can be applied into and contained within the structure where it penetrates the contents and kills all pests within. Like whole-room heat treatments, fumigation has no lasting effect (it leaves no pesticide residue), is labor-intensive, and can damage contents. It is also more expensive, especially in northern states where fumigations are done less frequently. The advantage of fumigation over heat treatment may be that fumigation is more likely to kill all the pests within a structure.
Move your bed away from the wall and put on a bedbug-proof cover, which may be called an encasement or liner. You’ll want to do the same for your box spring if you have one. Unless you have a severe infestation, you may not need to get rid of your mattress. Your exterminator can help you decide if that’s a good option. Either way, it’s important to wait until after treatment is complete to bring a new mattress into your home to avoid it becoming infested, too. (4, 5)
Prepare the room by separating treated from untreated furniture.  This will involve moving all your furniture to one side of the infested room (Remember, you’ve already assessed which rooms you think are infested.  You may not need to do this in every room).  The process is important because if you treat half of the items in a room and leave other areas untreated, bed bugs may return to the previously treated areas from untreated sites. Take all clothes from drawers, infested closets, etc. and double bag them in clear plastic bags (clear bags are easier to see where things are). Also double bag all personal items (toys, papers, books, electronics, CDs, or anything that could serve as a hiding place for bed bugs) and set them aside until they can be carefully treated, cleaned or inspected. 
Some bed bug species are parasites of bats or birds, and may bite people if the wild hosts are no longer available. Although similar in overall appearance, the species of bed bugs that normally feed on bats, swallows, chimney swifts, pigeons or other wild hosts can be differentiated from those that prefer humans. Entomologists and knowledgeable pest managers can make this determination. If bat bugs or bird bugs are present, roosting and nesting sites should be the primary focus, and the animals should be removed and excluded from the building.