Handwarming

Hopefully you are enjoying the heat of August, and staying cool while we enjoy record breaking heat in many states. This time of the summer is often when we feel the panic of the season slipping away, preparing to enter into the fall season of back-to-school and changing our wardrobes. It may seem slightly out of season, then, to discuss handwarming at a time when most of our hands are staying pretty toasty, but it is such a simple, tangible, and effective clinical tool that it is worthy of a blog post. Hand warming, also described as temperature biofeedback, is a form of self-regulation that allows a small probe to be heated, or warmed, by the skin temperature. Recall that biofeedback is a broad term that describes an approach in which a subject is given some type of information, perhaps in the form of an audio or visual signal, which is related to the subject's physiologic response to an intervention or experience.

According to the very thorough textbook "Biofeedback: A Practitioner's Guide" by Mark Schwartz and Frank Andrasik (3rd edition), the measurement of changing skin temperature is meaningful because sympathetic arousal is correlated to vasoconstriction. When the nervous system is calmed, and the blood vessels dilate, more heat is allowed into the local vessels thereby increasing local temperature. I was first introduced to the clinical tool of "handwarming" using a thermistor by Janet Hulme who taught a wonderful course on the topic of fibromyalgia. On her website she offers a device called the PhysioQ for $25. That seems like the going rate for many of the devices on the market, including this "stress thermometer" sold by bio-medical.com. The bio-medical site also has a terrific page explaining the concept of handwarming as well as specific strategies to apply for teaching its use. Click here to access that page.

The instruction in the clinic of handwarming can be billed as part of your home program training. In this time of decreasing reimbursement and emphasis on self-care, a device such as a thermistor could be a perfect training tool for your patient who wants to continue to manage stress, tension, and to use handwarming as a part of his or her rehabilitation program. The great thing about devices that give feedback is the instant gratification and measure of success that a patient can achieve when the ability to monitor and influence physiologic measures is seen. A thermistor typically has a wire that terminates in a sensor that can be attached (with tape or a little piece of velcro) to the underside of a fingerpad. The readout is observed in degrees, and some devices will have the ability to set goals or use tones for audio feedback. The use of a thermistor has been documented in the literature for the treatment of Reynaud's syndrome, migraines, and other conditions that have a stress-related component.

Schwartz & Andrasik recommend considering the following to avoid "artifact" which can alter the accuracy of readings when using temperature biofeedback.

• A very cool room can also cool the sensor.
• A very hot room will affect the ability of the subject to reduce heat in the hands.
• When coming in from the cold, allow the hands to warm to room temperature first.
• Avoid placing a blanket or other item that will restrict air flow and affect the sensor.