Evaluation of Experimental and Commercial Air-Activated, Adhesive Backed Heat Patches

Inclusion Criteria: * Participants are 18 to 70 years of age; * must be in general good health; * must have absence of any visible disease that might be confused with a skin reaction to the test material; * back region must be free from excessive hair, cuts, tatoos, or other aberrations; * must understand and sign Informed Consent; * must be considered dependable and able to follow directions; * Participants assigned to the thermocouples must be willing to restrict their activity for the 8 hour patch wear time so that the thermocouples do not come loose; * Participants assigned to the thermocouples must be willing to wear a pouch containing the thermostat and thermocouple wiring for the entire 8 hour period and to return all study supplies to the site at visit 15. If the items are not returned subject may be invoiced for the value of the unit; * must be willing to not wear any topical products such as lotions, sunscreens, etc. in the test area while participating in the study; * must agree to use an adequate means of birth control which include: abstinence, partner vasectomy, Intrauterine Device, hormonal implant devices/injections, regular use of birth control pills, birth control patches or condoms with a spermicidal agent; * Participants are willing to come in each day with a CLEAN back; * Participants who are 55 years of age and older, agree to supply a t-shirt to wear at visit two that can be marked on with a marker, and to use that t-shirt or supply others at the morni…