The goal of this clinical trial is to investigate whether there are differences in skin temperature at local or distal sites following Fu's Subcutaneous Needling (FSN) treatment or acupuncture treatment, and compare the extent to which FSN or acupuncture induces an increase in skin temperature in healthy population. The main questions it aims to answer are:

1. Fu's Subcutaneous Needling (FSN) treatment increases local blood perfusion, thereby elevating skin temperature.
2. The ability of FSN treatment to increase skin temperature is not inferior to that of acupuncture and may, in fact, be superior.

Researchers will compare the skin temperature changes among three groups which are FSN, acupuncture and control group to see if there are statistically significantly changes .

Participants will enroll into three groups which are FSN, acupuncture and no any intervention respectively.

Human physiological thermoregulation involves adjustments in heat dissipation and heat production in response to various internal and external thermal stimuli. The central control of thermoregulation is located in the preoptic/anterior hypothalamus (PO/AH) of the brain. Information about internal core and surface skin temperatures is transmitted to the PO/AH, which then coordinates appropriate responses. Skin blood flow is regulated by sympathetic nerve fibers, which release norepinephrine. When the core or surface temperature decreases, the intensity of sympathetic nerve activity increases, causing vasoconstriction at the arteriovenous anastomoses, resulting in reduced blood flow and decreased heat loss. Conversely, when the core or surface temperature increases, reduced sympathetic activity leads to vasodilation.

Numerous studies have utilized measurements of skin temperature and skin blood flow in traditional Chinese medicine research. Fu's subcutaneous needling therapy is widely used for treating conditions related to myofascial trigger points, as it is theorized to relieve the energy crisis that causes these trigger points by increasing blood perfusion in the affected muscles. However, fundamental research has not yet been completed to verify this theory. Therefore, this project aims to use skin temperature detection to determine whether Fu's subcutaneous needling can increase local skin blood perfusion and, compared to acupuncture, which method is more effective in raising skin temperature.

This study plans to recruit 60 healthy participants, who will be randomly assigned to the FSN group, acupuncture group, and control group. The participants will lie quietly in a temperature- and humidity-controlled room with nine detection points adhered to the right forearm. The entire experiment, including a 15-minute static phase, a 15-minute intervention phase, and a 3-minute post-intervention phase, will last 33 minutes. The researchers will record skin temperature every three minutes during the intervention and post-intervention phases, for a total of six recordings. Additionally, the investigator will measure changes in the hemodynamic parameters of the right forearm's radial artery using ultrasound before the static phase and after the post-intervention phase. Statistical analysis will be conducted on the changes in skin temperature at each detection point and hemodynamic parameters at radial artery.

Inclusion Criteria:

• Voluntary participants aged 18 years or older, of any sex, who are able to fully comply with the experimental procedures.
• Recent medical examination confirming the absence of cardiovascular, respiratory, gastrointestinal, urinary, hematological, endocrine, and neurological disorders.
• Normal communication ability, with the capacity to understand and follow instructions related to Fu's Subcutaneous Needling (FSN) and acupuncture treatments.
• Provision of written informed consent.

Exclusion Criteria:

• Diagnosis of psychiatric disorders, severe depression, alcohol dependence, or a history of substance abuse.
• Pregnancy or breastfeeding.
• Presence of local skin infection, ulceration, or injury at the treatment site.
• Participation in other clinical trials.