This is an open-label study. A total of approximately 60 subjects will be randomly assigned to receive either the heat patch (30 subjects) with a temperature probe/skin reference probe or a heat patch (30 subjects) alone. The study will consist of 2 visits.

Inclusion Criteria:

• Subjects who complete an appropriately administered informed consent process that includes signing the consent form.
• Subjects 18-75 years old of either sex.
• Are of any skin type or race, providing the skin pigmentation will allow discernment of erythema;
• Subjects who are in good general health.
• Subjects who are willing and able to have the test products applied as directed, and comply with study instructions.
• Participants must be willing to restrict their activity for the 8 hour patch wear time.
• All participants agree to wear a t-shirt provided by the site for the entire 8 hour patch wear time.

Exclusion Criteria:

• Subjects who have a history of sensitivity to any of the test products or adhesion material.
• Subjects who are pregnant.
• Subject with excessive hair at the application sites, scar tissue, tattoo, or coloration that would interfere with placement of test product or skin assessment.
• Subjects with diabetes, rheumatoid arthritis, poor circulation or have any clinically significant chronic illness.
• Subjects with active dermatitis (including sunburn) in the treatment area, or other visible dermatological disease which, in the investigator's opinion, might interfere with the response to the test products or interfere with the skin assessments associated with the test products.
• Have history of significant dermatologic cancers (eg, melanoma, squamous cell carcinoma).
• Subjects who have used topical dermatological products in the application area within 24 hours prior to the test product application.
• Subject using a concomitant medication that, in the investigator's opinion, could interfere with the interpretation of study results. Examples of such drugs include non-steroidal anti-inflammatory drugs (NSAIDs, e.g., aspirin), topical or systemic corticosteroids, and cold/cough products containing antihistamines and/or either phentolamine, pseudoephedrine or phenylpropanolamine.
• Subjects who have received an investigational medication or device within 30 days prior to enrolment into this study.
• Subjects who are currently participating in an investigational study.
• Subject who are known to be noncompliant or are unlikely to comply with the requirements of the study protocol (e.g., due to alcoholism, drug dependency, mental incapacity) in the opinion of the investigator.