Once the phlebotomist has successfully identified the patient, the next step of the dermal puncture procedure is to locate and determine a site suitable for puncture. If a heelstick in an infant is being performed, the phlebotomist should apply a warming device for approximately 3-5 minutes to the heel to increase blood flow to the area, which will facilitate the collection of the capillary specimen. The use of a warming device is also recommended when a fingerstick is performed, if the hands are cool to the touch.
A heat-standardized, pre-packaged, chemically activated heel warmer, or comparable heating agent should always be used to warm the heel of an infant to prevent scalding or burning. The temperature of the heating device should not exceed 42°C.
Caution-- do not use a cloth that has been moistened and warmed in a microwave oven. This may have hot spots that could cause injury to the patient. It is also not advisable for the phlebotomist to hold a patient's hand under hot running water. This again could cause an injury. If feasible, the patient could be instructed to warm his or her own hands under running water, but allow the patient to adjust the water temperature.