Infrared light therapy with cold-water immersion

13) A method of delivering therapeutic cold immersion with infrared light therapy, comprising:

• a) immersing at least a portion of a user's body including the face in water maintained at or below 50° F. (10° C.);
• b) irradiating the submerged tissue with near-infrared light at wavelengths between 800-880 nm at an average irradiance of 60-160 mW/cm2 measured through a water path of 15-40 mm for a duration of 20-180 seconds;
• c) wherein the water acts as an optical filter attenuating wavelengths greater than 1400 nm and as a thermal sink maintaining the epidermal temperature below 32° C.;
• d) and wherein the irradiation delivers at least 3-10 J/cm2 to the dermal or sub-dermal tissue, producing:
• i) autonomic modulation defined by a heart-rate reduction of at least 5-15% within 60-120 seconds and/or a heart-rate variability (RMSSD) increase of at least 10-20% within five minutes post-treatment;
• and
• ii) cosmetic improvement defined by periorbital puffiness reduction and improved skin tone or firmness within 15-60 minutes without erythema greater than 5% over baseline.