Comparison of Bi-environmental Conditions During Occupational Related Activity
Condition: Hyperthermia; Hypothermia
MeSH terms: Hypothermia; Hyperthermia
Study type: Interventional

Summary: 
      BHSAI is developing a computational system that provides early alerts of a rise and fall in
      core body temperature to help reduce the risk of thermal injury in the field and during
      training. The goal of the body temperature alerting system is to use it during rest, exercise
      in the heat and cold. Therefore, the primary purpose of this investigation is to validate a
      body temperature alerting system using physiological responses that occur during rest,
      exercise in the heat and cold. Multiple cold ambient temperatures will be validated.
    

Detailed description: 
      Each participant will perform 5 study visits: 1) baseline testing and four trials.

      Participant numbers will be randomly assigned. Four trials for men (extreme cold, EC;
      Moderate Cold, MoC; mild cold, MiC; extreme heat, EH) and four trials for women
      (EC-follicular phase, EC-F; EC- luteal phase, EC-L; EH-F; EH-F) will be ordered with a random
      number generator and assigned to a participant number. These orders will be counterbalanced
      between participants to ensure that there is not an order effect. 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 (Appendix H) 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.

      Baseline Testing (visit 1)

      Participants who are approved to participate will be scheduled for a baseline and VO2max

      testing day. Upon arrival to the lab, subjects will provide a urine sample in a clean urine
      cup.

      Urine specific gravity and urine color will be assessed. Nude body mass will also be
      recorded. Privacy will be afforded for each participant while obtaining body mass measures by
      taking measurements with the participant alone in a private room behind a solid, closed door,
      and the research reading the scale outside of the room. Participants will only be permitted
      to continue to

      the VO2max test if the euhydrated criteria of a urine specific gravity (USG) ≤1.025 is met.
      If the participant arrives with a USG between 1.020 and 1.025, the subject will be asked to
      drink 500mL of water to ensure proper hydration status. Participants will fill out a
      Karolinska Sleep Diary (Appendix I) prior to collecting anthropometrics. Females will fill
      out a menstrual history questionnaire (Appendix K). Height will be measured with a tape
      measure. Percent body fat will be measured using Air displacement plethysmography (BodPod®;
      Cosmed, Software Version 4.2+, Concord, CA, USA). This will take less than ~5 minutes to
      complete. This information will be used to describe the subject demographics. For
      familiarization purposes, researchers will insert and immediately remove the esophageal
      probe. Participants will also be asked to complete a maximal oxygen uptake (VO2max) test on a
      treadmill in a thermoneutral environment. This test will provide aerobic fitness levels of
      the participants. After VO2max testing, researchers will assess the 6 locations where blood
      flow analyses will occur during trial days (described in the dependent variable section).
      This will familiarize the participant to the blood flow process and allow researchers to
      optimally location each artery of interest prior to the testing days. Researchers may also
      use a sharpie or tracing paper to mark anatomical landmarks to assist with artery
      identification during trial days. This visit will take approximately 1-2 hours.

      Substudy #1 Males and Females in Extreme Cold and Heat

      This substudy will have two visits for males and four visits for females (figure below).

      Participants will perform 30 mins of rest outside the climate chamber, one hour of rest
      inside the climate chamber, and 2 hours of work to rest cycles in the climate chamber.

      Participants will be allowed to make-up trial visits if they are sick, suffer an injury or do
      not meet hydration requirements. Participants will be asked if they have a current illness or
      taking medications to determine whether they can complete the trial. The participant's visit
      will be rescheduled if they have a fever, current illness or taking medications that
      influence body temperature. Both trials will be on separate days at least 3 days apart. Women
      will determine their phase of their menstrual cycle based on self-reporting and a menstrual
      history questionnaire filled out during the baseline visit (Appendix K). The EC and EH trials
      in the follicular phase will be collected 14 days following the start of menses and the
      luteal phase will occur between 14 and ~30 days of cycle.

      Upon arrival to the lab, subjects will provide a urine sample in a clean urine cup. Urine
      specific gravity and urine color will be assessed. Nude body mass will be recorded. Privacy
      will be afforded for each participant while obtaining body mass measures by taking
      measurements with the participant alone in a private room behind a solid, closed door, and
      the research reading the scale outside of the room. Participants will only be permitted to
      continue to the trial if the euhydrated criteria of a urine specific gravity (USG) ≤1.025 is
      met. If the participant arrives with a USG between 1.020 and 1.025, the subject will be asked
      to drink 500 mL of water to ensure proper hydration status.Participants will be given
      instructions at the prior visit about how to obtain desired hydration status for the upcoming
      trial.

      Upon arrival to the lab, participants will also be asked to indicate if they have consumed
      alcohol or caffeine in the last 24 hours and 12 hours, respectively. They will not be asked
      to specify exactly what they have consumed, but if they provide a positive indication, their
      trial will be rescheduled for another day. Key study personnel will insert an esophageal
      probe to measure esophageal temperature (procedure described below). No undergraduate student
      who is listed as key personnel will insert an esophageal probe Participants will privately
      insert a rectal thermometer 15 cm beyond the anal sphincter and wear a heart rate monitor
      strap. Additionally, participants will wear 14-site skin temperature sensors (Biopac).
      Researchers will apply the skin temperature sensors with medical tape to the participants'
      finger tip and base of finger, hand dorsum, forearm, thigh, calf, feet dorsum, big toe, nose,
      cheek, ear tip, chin, and forehead. Participants will also have 4 iButton skin temperature
      sensors placed on four locations (shoulder, chest, calf, thigh) to assess mean skin
      temperature. The participants will also be asked to complete a subjective sleep questionnaire
      upon arriving to the lab. 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 would be provided by the BHSAI to the University of
      Connecticut.n addition to the BHSAI-provided devices, participants will wear an apple watch
      and garmin watch on the opposite hand. Both of these devices will be validated against the
      gold standard assessments (Table 2). Each dependent variable coming from the Apple and Garmin
      devices from the manufacturer's own applications. All measurements will be taken starting
      from the thermoneutral exposure (pre-exposure) period to include baseline recordings. Blood
      flow of the brachial artery, radial and ulnar artery, superficial femoral artery, anterior
      tibial artery, and posterior tibial artery will be collected with a Triplex ultrasound during
      rest (before exercise and during rest breaks). The same sequence for the measuring sites
      across subjects, e.g., 1) radial, 2) ulnar, 3) brachial, 4) femoral, 5) anterior tibial, and
      6) posterior tibial, will be used. A pulse oximeter will also be clipped to the participant's
      finger and measured every 10 mins throughout each rest period. Blood lactate will be assessed
      from a finger stick blood sample (0.7μ1) during exercise trials and post-exercise. VO2 data
      will also be assessed to collect metabolic heat production. After thermoneutral exposure of
      30 minutes, participants will rest in a lounge chair for an hour and then perform 2 hours of
      moderate exercise with rest breaks. All dependent variables listed above will be collected
      through the exercise period at various time points. Participants will drink ad libitum
      throughout the exercise trial. Participants will be asked to keep a dietary record (using My
      Fitness Pal) to track their food and fluid intake during the trial period.

      Extreme Cold Trial

      During the EC trial, participants will wear a t-shirt, shorts, a microfleece cap and
      lightweight balaclava. Participants will also wear ankle length socks (no shoes during rest).
      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 up to 1 hour. For
      additional safety of the participants, the experiment will be terminated if the core body
      temperature falls below 35°C. Participants will wear t-shirt, shorts, microfleece cap, and
      shoes for the exercise component of the protocol. The trial will be conducted outside the
      chamber (~20C) and in a climatic chamber with ambient temperature below <8°C and relative
      humidity at approximately 30%.

      Extreme Heat Trial

      During the EH trial, participants will wear a t-shirt and shorts, a microfleece cap and
      lightweight balaclava during rest. Participants will also wear ankle length socks (no shoes
      during rest). Participants will remove the cap and balaclava prior to exercise. During rest,
      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 up to 1 hour. For
      additional safety of the participants, the experiment will be terminated if the core body
      temperature exceeds 40C. Participants will wear t-shirt, shorts, microfleece cap, and shoes
      for the exercise component of the protocol. The trial will be conducted outside the chamber
      (~20C) and in a climatic chamber with ambient temperature between 30-42C and relative
      humidity at approximately 30-60%. Participants will also complete an environmental symptoms
      questionnaire (ESQ).

      Substudy #2 Males Moderate and Mild Cold Stress at Rest

      Participants will perform 30 mins of rest outside the climate chamber and two hours of rest
      inside the climate chamber in moderate vs. mild cold (Figure 3). The data collection
      procedures are summarized below and in Figure 3. The subjects will be male only and will the
      same male subjects participating in substudy #1.

      Trial Day Procedures (moderate and mild cold).

      Participants will be allowed to make-up trial visits if they are sick, suffer an injury or do
      not meet hydration requirements. Participants will be asked if they have a current illness or
      taking medications to determine whether they can complete the trial. The participant's visit
      will be rescheduled if they have a fever, current illness or taking medications that
      influence body temperature. Both trials will be on separate days at least 3 days apart. Upon
      arrival to the lab, subjects will provide a urine sample in a clean urine cup. Urine specific
      gravity and urine color will be assessed. Nude body mass will be recorded. Privacy will be
      afforded for each participant while obtaining body mass measures by taking measurements with
      the participant alone in a private room behind a solid, closed door, and the research reading
      the scale outside of the room. Participants will only be permitted to continue to the trial
      if the euhydrated criteria of a urine specific gravity (USG) ≤1.025 is met. If the
      participant arrives with a USG between 1.020 and 1.025, the subject will be asked to drink
      500 mL of water to ensure proper hydration status.

      Upon arrival to the lab, participants will also be asked to indicate if they have consumed
      alcohol or caffeine in the last 24 hours and 12 hours, respectively. They will not be asked
      to specify exactly what they have consumed, but if they provide a positive indication, their
      trial will be rescheduled for another day. Key study personnel will insert an esophageal
      probe to measure esophageal temperature (procedure described below). No undergraduate student
      who is listed as key personnel will insert an esophageal probe Participants will privately
      insert a rectal thermometer 15 cm beyond the anal sphincter and wear a heart rate monitor
      strap. Additionally, participants will wear 14-site skin temperature sensors. Researchers
      will apply the skin temperature sensors with medical tape to the participants' finger tip and
      base of finger, hand dorsum, forearm, thigh, calf, feet dorsum, big toe, nose, cheek, ear
      tip, chin, and forehead. Participants will wear a 3-lead ECG device. The participants will
      also be asked to complete a subjective sleep questionnaire upon arriving to the lab. 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 would be provided by the BHSAI to the University of Connecticut. All measurements
      will be taken starting from the thermoneutral exposure (pre-exposure) period to include
      baseline recordings. Blood flow of the brachial artery, radial and ulnar artery, superficial
      femoral artery, anterior tibial artery, and posterior tibial artery will be collected with a
      Triplex ultrasound during rest (before exercise and during rest breaks). The same sequence
      for the measuring sites across subjects, e.g., 1) radial, 2) ulnar, 3) brachial, 4) femoral,
      5) anterior tibial, and 6) posterior tibial, will be used. VO2 data will also be assessed to
      collect metabolic heat production. A pulse oximeter will also be clipped to the participant's
      finger and measured every 10 mins throughout each rest period. Blood lactate will be
      initially assessed using a finger stick blood sample (0.7 μ1) during the baseline period
      (thermoneutral). After thermoneutral exposure of 30 minutes, participants will rest in a
      lounge chair for two hours. All dependent variables listed above will be collected through
      the exercise period at various time points. Participants will drink ad libitum throughout the
      exercise trial. Participants will be asked to keep a dietary record (using My Fitness Pal) to
      track their food and fluid intake during the trial period. Participants will wear a t-shirt,
      shorts, and microfleece cap. Participants will also wear ankle length socks (no shoes).
      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 up to two hours. For
      additional safety of the participants, the experiment will be terminated if the core body
      temperature falls below 36°C. The trial will be conducted outside the chamber (~20C) and in a
      climatic chamber for moderate cold will have an ambient temperature between 8-10°C and mild
      will be 10-15C (relative humidity at approximately 30% for both).
    

Intervention name(s): Zero Degrees Cold Environment; Eight Degrees Cold Environment; Ten Degrees Cold Environment; 40 degrees Hot Environment
Intervention type(s): Other; Other; Other; Other
Intervention description(s): Participants will be exposed to zero degrees celsius environment.; Participants will be exposed to eight degrees celsius environment.; Participants will be exposed to Ten degrees celsius environment.; Participants will be exposed to 40 degrees celsius hot environment.
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Intervention model description: men are exposed to four conditions (3 cold conditions at 0, 8, 10C and 40C heat) women are exposed to four conditions (2 cold conditions- follicular and luteal phase; 2 heat conditions follicular and luteal phase)
Masking: None (Open Label)
Primary purpose: Other