ENVIRONMENTAL PARAMETERS ON SWEAT GLAND ACTIVITY 245 time. These data provided us with suffi cient information to establish appropriate testing parameters, ensuring that we used proper quantities and induction times in the test pro- tocol. To understand the variability of sweat output, we carried out gravimetric measure- ments to monitor the kinetics of sweat uptake by absorbent pads placed in the axillae. Proper choice of equilibration times in the environmental room required that we also conduct fl ux measurements of water vapor diffusion, which were carried out on the inner forearm. In addition, we used thermal infrared (IR) imaging to map the temperature distribution across all surface anatomical regions. This allowed us to monitor the heating (environmentally controlled) and subsequent cooling (eccrine sweating) of various regions of the body. Based on the combined results of the gravimetric kinetic studies, fl ux mea- surements, and IR thermal imaging, we fi nd that our choice of parameters (temperature, relative humidity (RH), and acclimatization times) for the skin replica studies is valid. MATERIALS AND METHODS Sweat gland activity was monitored using gravimetric analysis and skin replica techniques. We carried out gravimetric analysis to monitor sweating in the axillae. Skin replicas were obtained from the inner forearm and later analyzed using image analysis techniques— providing the quantity of active glands per unit area. Two different tests were conducted, one where the subjects spent 30 min in the sauna (Test 1) and the other 45 min (Test 2). Replicas and gravimetric analysis were carried out simultaneously in Test 1, whereas only gravimetric analysis was completed in Test 2. We used various temperature and humidity control conditions in the sauna, which are indicated in the Results and Discussion section. Unless otherwise indicated, the subjects were acclimatized in an environmental room prior to entry into the sauna—for both Tests 1 and 2. In addition, we carried out DMA studies of the replica formulation to ensure proper mixing and curing kinetics. Flux density measure- ments were used to corroborate the chosen acclimatization schedule. Thermal imaging al- lowed for the determination of the anatomical temperature distribution in the subjects as a function of time and the selected environment. QUANTIFICATION OF SUDORIFEROUS BEHAVIOR An environmental room was constructed to house a sauna and also to serve as an acclima- tization area for subjects prior to entry into the sauna. We designed the room in such a manner as to provide a serene environment allowing the subjects to experience similar comforts and sentiments as in a spa. After the installation of a ceramic fl oor, the entire room was painted and decorated using modern decor. The underlying walls and fl oor of the environmental room are constructed of concrete thereby preventing excessive tem- perature/humidity loss from the room and temperature/humidity invasion from the ex- ternal environment. The dimensions of the environmental room are 5 m length, 2.5 m width, and 2.2 m height. The sauna, Model FRB-022LCND, was purchased from Sauna King Products, San Leandro, CA. It is an IR sauna constructed of cedar wood and has fi ve internal heaters. The operating temperature is between 30°C and 60°C (86°F and 140°F). The humidity inside the chamber is controlled with a humidifi er (Model HM5082 Holmes, Boca Raton, FL) connected to a humidity controller (Model 5200 Electro-tech Systems,

JOURNAL OF COSMETIC SCIENCE 246 Inc., Glenside, PA). Inside the environmental room, temperature and humidity are also controlled using two fl oor heaters (Model HZ-519 Honeywell, Morristown, NJ) and a cool mist humidifi er (Model HM3655 Holmes, Boca Raton, FL). During testing, temperature, humidity, and dewpoint were monitored every minute in the sauna, in the environmental room, outside the environmental room in the building, and outside of the building in a shaded area. These data were recorded using data loggers (Model DVTH 421-338-0023 purchased from Supco, Allenwood, NJ), and were transferred to computer by USB cable where they could be analyzed using software provided by Supco. The barometric pressure was also recorded at the beginning of all experimental sessions using an aneroid (mechani- cal) barometer (Model Proteus Maximum Inc., New Bedford, MA). Unless otherwise indicated, subjects are allowed to acclimate for 30 min in the environ- mental room prior to entry into the sauna. During this time, they are discouraged from engaging in stressful conversation or work-related reading. The temperature and humid- ity of the room are (normally) maintained constant at approximately 28°C (84°F) and 40% RH, corresponding to a dew-point temperature of roughly 14°C (57°F) and satura- tion vapor pressure of 3.98 kPa. All subjects were dressed in a uniform consisting of cot- ton slacks (Model RN85080 La Difference, Mexico) and cotton T-shirts (I2701 Fruit of the Loom, Inc., Bowling Green, KY). For safety reasons, the blood pressure and pulse rate of each subject were recorded before entry into the sauna using a blood pressure monitor kit (Model HEM-780 Omron, Kyoto, Japan). If blood pressure readings indicated any degree of hypertension, the subject was immediately dismissed from participating in the test. The following guidelines were used to determine the level of severity of hyperten- sion: mild hypertension (systolic blood pressure = 140–160 mm Hg diastolic blood pressure = 90–100 mm Hg), moderate hypertension (systolic blood pressure = 160–200 mm Hg, diastolic blood pressure = 100–120 mm Hg), and severe hypertension (systolic blood pressure = above 200 mm Hg, diastolic blood pressure = above 120 mm Hg). We measured resting heart rate (no physical exertion) and eliminated any subjects from the study whose monitored values were greater than 90 bpm. Once the subject reached equilibrium in the environmental room, they entered the sauna for a total of either 30 (Test 1) or 45 min (Test 2). In Test 1, the fi rst 10 min is an equi- librium period followed by a 20 min sweat production period. At t = 10 min, the subject was given two pre-weighed feminine hygiene pads (Stayfree, Ultrathin Overnight Pads with Wings McNeil-PPC, Inc., Skillman, NJ), which they place (folded) in the left and right axillae. At t = 30 min, the weight of the absorbent pad is measured using an elec- tronic balance (Scout Pro Balance, Ohaus, Pine Brook, NJ). After the pad is weighed, replica measurements are conducted. In Test 2, the subject enters the chamber and is im- mediately given the pads to place in the axillae. The pads are weighed every 5 min until the conclusion of the test. In Test 1, we recruited more than 25 subjects, both male and female, from diverse racial backgrounds and ranging in age from 30 to 45 years. In Test 2, two male subjects participated in a battery of range-fi nding experiments. Subject 1—38 years old, 62 in. height, 135 lb. weight, and of Chinese origin. Subject 2—43 years old, 70 in. height, 175 lb. weight, and American of Northern European ancestry. These two subjects had no history within the last 5 years of antiperspirant usage. In several experiments, subjects were preconditioned using an exercise bike (Schwinn Ac- tive 10 Series Nautilus Inc., Vancouver, WA). In other experiments, subjects were placed in a cool room (2°C and 80% RH) for the fi rst 30 min of the test, then directly entered the sauna. Also, the infl uence of hot (76°C) and room temperature (22°C) water ingestion