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.

Some firms want beds stripped and furniture moved before they arrive, while other firms prefer to inspect first and perform these tasks themselves. Clutter and belongings on floors (especially beneath beds) must be removed since they impede treatment and afford additional places for bugs to hide. Bedding and garments normally will need to be laundered and/or hot dried (120°F minimum) since they cannot be treated with insecticides. An effective and efficient alternative to laundering is to simply place bedding, clothing, toys, shoes, backpacks, etc., in a clothes dryer set at medium-to-high heat for 10 to 20 minutes. This can be done in lieu of washing and will kill all bed bug life stages. 
My daughter stayed at a friends for 2 nights…. And brought home bedbugs!! She has bites from the top of her head to her feet. The itching must be horrific. Poor child. After 2 days of not being able to stop the itching, as a last resort (on a Sun at 11pm) I told her to use a bathroom spray cleaner that had bleach in it. She only put it on her legs, but the itching stopped there, just not on arms, stomach or in her head. Don’t recommend bleach but she was able to get a couple hours of sleep. I will try several things to try to help her that I have read from previous comments. Thanks everyone….

Cutaneous reactions to bedbug bites can vary widely and are easily confused with other conditions (Table 1).15–19 A typical lesion is a 2- to 20-mm, pruritic, erythematous maculopapule with a central hemorrhagic crust or vesicle.5,8 Macules, papules, wheals (Figure 3), vesicles, bullae, and nodules have all been reported,20 as have asymptomatic lesions with a barely visible punctum as the only evidence of a bite.8 Bites vary in number and are preferentially distributed in unclothed areas (e.g., face, neck, extremities). Unlike many other arthropod and insect bites, bedbug bites are rarely located in the popliteal fossae or axillae.21 Lesions can be noticeable immediately when waking up or several days later, with the reaction often progressing from delayed to immediate with subsequent exposures22–26  (Table 2). The classic bedbug rash is referred to as “breakfast, lunch, and dinner” because it commonly presents as several bites in a row or cluster 20 (Figure 4).
Bed bugs are active in summer and winter and are not considered "seasonal" in the same sense that mosquitoes, ticks and stinging insects are. Still, many consider bed bugs to be a greater problem in the warmer months, however it is not the bed bugs that are more active in the summer months - the humans are. In warmer weather we typically travel more, often sleeping in hotels and motels, using various modes of transportation, and thereby increasing our risk of exposure to bed bugs. The bed bugs themselves are year-round pests.
Insecticides might also have their work cut out for them: Entomologists have known that the common bedbug has built up resistance to some typical insecticides such as those containing certain pyrethroid chemicals like deltamethrin, according to Entomology Today. Deltamethrin apparently paralyzes an insect's nervous system, according to Cornell University.
Bed bugs tend to congregate, but it’s also common to find a single bug or some eggs here and there. A thorough inspection and treatment may take up to several hours. Some companies use specially trained dogs to assist in finding small dispersed infestations, especially in such places as hotels, schools, libraries and office buildings. When properly trained, bed bug detection dogs can be quite effective. Relatively few companies are routinely using them, however, due to the expense of training and maintaining such animals. Reliability of some of the dogs is also being questioned as more enter the market.    
While cleaning up infested areas will be helpful in controlling bedbugs, getting rid of them usually requires chemical treatments. Because treating your bed and bedroom with insecticides can be harmful, it is important to use products that can be used safely in bedrooms. Do not treat mattresses and bedding unless the label specifically says you can use them on bedding.