Indoor Overheating and Physiological Strain in Older Adults With COPD

Potential changes in mood (7 subscales of mood: tension, anger, depression, fatigue, confusion, vigor and esteem-related affect). The POMS-40 is a validated, self-administered questionnaire that examines seven distinct aspects of mood state across two positive subscales (Esteem-Related Affect, and Vigor) and five negative subscales (Fatigue, Tension, Confusion, Anger, and Depression), which are described across 40 distinct adjectives. For each individual item, participants were asked to describe "how you feel right now" by responding using a 5-point Likert scale (0 = "Not at all", 1 = "A little", 2 = "Moderately", 3 = "Quite a lot", or 4 = "Extremely"). The values of items associated with a specific subscale (e.g., Fatigue) were summed to calculate its score.

Self-reported environmental reactions and medical symptomatology associated with prolonged heat exposure. The ESQ-IV is a validated 68-item, self-administered questionnaire that has been used successfully in identifying symptomatology during exposure to a wide variety of environmental conditions, including heat exposure [24, 25]. Participants are asked to assess and described "how you have been feeling today" by responding to each item using a 6-point Likert scale (0 = "Not at all", 1 = "Slight", 2 = "Somewhat", 3 = "Moderate", 4 = "Quite a bit", or 5 = "Extreme"). Total Symptom Score was calculated from this data by taking the sum of the intensity ratings from all 68 individual items using reverse scores for the three positive items from the list ("I Felt Good", "I Felt Alert", and "I Felt Wide Awake").

Cumulative sum of scores on 6 questions asking participant to rank symptoms associated with orthostatic intolerance during the lying to standing tests. All symptoms scored on a scale from 0 (none) to 10 (worst possible) and include feelings of: (1) "dizziness, lightheadedness, feeling faint, or feeling like you might black out"; (2) "Problems with vision (blurring, seeing spots, tunnel vision, etc.)"; (3) "Weakness"; (4) "Fatigue"; (5) "Trouble concentrating"; and (6) "Head and neck discomfort".

Perceived arousal assessed using the Felt Arousal Scale, a single-item 6-point numerical rating scale on which participants respond to the question "How worked up are you?" Scores range from a minimum of 1 (low arousal) to a maximum of 6 (high arousal).

Perceived thirst assessed using the Thirst Sensation Scale, a single-item 9-point numerical rating scale on which participants respond to the question "How thirsty do you feel now?" Scores range from a minimum of 1 to a maximum of 9, with verbal anchors at 1 (not thirsty at all), 3 (a little thirsty), 5 (moderately thirsty), 7 (very thirsty), and 9 (very, very thirsty).

Thermal sensation assessed using the thermal sensation scale defined in ANSI/ASHRAE Standard 55 (American Society of Heating, Refrigerating and Air-Conditioning Engineers), a single-item 7-point bipolar rating scale on which participants respond to the question "How do you feel right now?" Scores range from a minimum of -3 (cold) to a maximum of +3 (hot), with 0 indicating a neutral thermal sensation.

Thermal comfort assessed using the thermal comfort scale defined in ANSI/ASHRAE Standard 55 (American Society of Heating, Refrigerating and Air-Conditioning Engineers), a single-item 4-point rating scale on which participants respond to the question "How comfortable do you feel right now?" Scores range from a minimum of 1 (comfortable) to a maximum of 4 (very uncomfortable).

Change in plasma volume from baseline values calculated from duplicate measurements of hemoglobin and hematocrit at the start and end of each exposure using the technique by Dill and Costill

Fluid loss calculated as the change in body mass during each exposure presented as a percentage of baseline body mass (corrected for food consumption)

Average hourly fluid consumption calculated by weighing participant water intake at the start and end of each hour of exposure (normalized to the exposure duration).

Root mean squared standard deviation of normal-to-normal R-wave to R-wave intervals (RMSSD) measured during 5 minutes of paced breathing (15 breaths/min) with participants in the seated position. RMSSD will be evaluated twice, during two paced breathing periods (separated by 4 min of seated rest).

Standard deviation of normal-to-normal R-wave to R-wave intervals (SDNN) measured during 5 minutes of paced breathing (15 breaths/min) with participants in the seated position. SDNN will be evaluated twice, during two paced breathing periods (separated by 4 min of seated rest).

Rate pressure product, an index of myocardial work and strain, calculated as systolic blood pressure x heart rate.

Diastolic blood pressure measured in triplicate via automated oscillometry (~60 seconds between measures)

Systolic blood pressure measured in triplicate via automated oscillometry (~60 seconds between measures)

Systolic blood pressure response to standing evaluated as the difference in blood pressure measured between the standing and supine. Standing systolic blood pressure will be taken as the lowest value of those measured after 60 and 120 seconds of standing. Systolic response to standing will be evaluated twice, during two lying-to-standing tests (separated by 10 min of supine rest).

To assess postural stability, participants hold a tablet to their chest, then auditory cues guide participants through four consecutive stances, feet side by side, instep of one foot touching the big toe of the other foot, tandem stand with one foot in front of the other, heel touching toe, and stand on one foot. The balance assessment will be evaluated based on movement detected by an accelerometer integrated into the hardware of the tablet device (Sway Medical Inc).

Participants will be provided with a tablet device with the Sway Medical testing platform for the assessment of executive function. Participants will complete the Cued Stroop test, in which they are presented a sequence of congruent, neutral and incongruent colour-word tasks.

Participants will be provided with a tablet device with the Sway Medical testing platform for the assessment of memory recall. Participants complete both a delayed recall test and a working memory test.

Participants will be provided with a tablet device with the Sway Medical testing platform for the assessment of impulse control. Participants will be asked to respond to both "go" and "no-go" visual cues. In response to the "go" cue, participants will initiate a movement of the device.

Participants will be provided with a tablet device with the Sway Medical testing platform for the assessment of reaction time. Participants will be asked to initiate a movement of the device in response to a visual cue.

Cardiac response to standing evaluated as the ratio between the highest R-wave to R-wave interval (lowest heart rate) measured at the 30th heart beat after standing from supine (+/- 5 beats) and the lowest R-wave to R-wave interval (highest heart rate) measured at the 15th heart beat after standing (+/- 5 beats). Cardiac response to standing will be evaluated twice, during two lying-to-standing tests (separated by 10 min of supine rest). Assessment is performed in the morning prior to and following daytime exposure.

Area under the curve of heart rate (in bpm-hours)

Peak Heart rate (15-min average) during the 8-hour exposure

Area under the curve of rectal temperature (in degree-hours)

Rectal temperature measured at each hour of exposure (15-min average)

Peak mean skin temperature (15-min average) during the 8-hour exposure

Area under the curve of mean skin temperature (in degree-hours)

Urine specific gravity measured by handheld refractometer