Safety and Performance Monitoring During Occupational Work II

This study will employ a randomized, cross-over design to assess the effect of three different cold ambient temperatures on skin temperature at peripheral regions, core temperature (rectal), metabolic heat production, hand dexterity measures at rest, and athletic performance assessment after rest in cold ambient temperatures. The three different trials for this study will include ambient temperatures at: A. 0°C (32°F), B. -10°C (14°F), and C. Surrogate -20°C (-10°C + 3 m/s wind speed [14°F + 6 mph]). This will be accomplished by use of a environmental chamber.

Participants will be assigned after medical clearance is granted. Visit specific information is described below, however, specific data collection protocols for dependent variables and procedures are included below the description of the study design. Participants will be asked to sign a photo/video release form to be used in research projects, scientific publications/conferences and for educational purposes. Participants may be videoed or photographed while exercising or resting in the environmental chamber.

During the 0°C (32°F) and -10°C (14°F) trials, participants will wear cold weather gear as described by BHSAI. All cold weather gear will be machine-washable, provided to the participants and properly fitted to each individual. Clothing will be kept in the laboratory, machine-washed by manufacturer recommendations. Participants will not be able to keep clothing used upon completion of the study. These trials will also have a wind speed of 1 m/s. For the surrogate -20°C (-4°F) experiment, ambient temperature will be -10°C (14°F) with wind speed approximately at 3 m/s (6 mph) to serve as an aggregate for -20°C (-4°F). Wind will not be facing the participant. Participants will wear all cold weather gear listed above with the exception of the microfleece cap and shell layer for hand (Figure 2). For all trials, participants will rest upright on a chair with feet above the ground and hands on the arms of the chair (exposed to air). The participant will remain seated for 120 minutes. For additional safety of the participants, the experiment will be terminated if the core body temperature falls below 35°C (95°F) and/or the skin temperature in any of the peripheral regions falls below 8°C (46°F). During the three testing sessions, the participants will wear a Samsung Gear S3 smartwatch on their non-dominant arm and a Polar chest strap. These devices would be paired with a Samsung Galaxy Note 4 smartphone that runs the 2B-Cool algorithm for core temperature estimation using data from the smartwatch. These devices will be used in conjunction with data from the rectal and skin temperature sensors to validate the sponsors' temperature prediction algorithm. All devices will be cleaned prior to and after participant use per manufacturer instructions. These devices would be provided by BHSAI to the University of Connecticut. During the three testing sessions, in addition to the BHSAI-provided devices, participants will wear thermistors to record the skin temperature (finger-tip and base of finger, hand dorsum, big toe, nose, cheek, ear tip, chin, and forehead and will privately insert a rectal thermometer 15 cm (~4-6 ins) beyond the anal sphincter to record the gold-standard core temperature.VO2 data will also be assessed to collect metabolic heat production. Hand dexterity will be assessed using the validated Purdue pegboard test.

During all three sessions, researchers will ensure that the smartwatch is placed approximately 1-inch proximal to the wrist and fits snuggly to ensure accurate heart-rate measurements. Researchers will also ensure that the devices are paired with the smartphone and the physiological variables are being recorded on the phone before commencement of the session. Since different devices will be used for measuring the physiological variables and the associated gold standard, researchers will record the starting time-stamp from the smartphone and the gold-standard recording computer to ensure time synchronization.

Following the 120-minute seated rest period, a performance battery will be utilized to assess athletic performance in 3 different cold environments. Agility/reaction time, power, muscular strength, sprint performance on a cycle ergometer, and 1-mile time trial on a motorized treadmill will be assessed. An environmental symptom questionnaire (ESQ) will be administered at the end of the performance battery prior to exiting the chamber. All trials will be approximately 3-4 hours each. Total participation in the study is approximately 12-14 hours of time for the participant.