Study on the effectiveness of personal cooling equipment for

protecting workers from heat stroke while working in a hot environment

1st lab test

5 Dec, 2012Del P. WONG, Guo Yueping, Jackio Yang

Report 15

OSHC Lab test protocol (29 November 2012)

Time Duration Task Remark

>8hrs from the test

Ingest the coreTemp pill

  -- Colleagues arrive the lab    30min Equipment preparation Turn on the chamber and set at 30oC and 75%

relative humidity  -- Participant arrives the lab    15min Explanation of study to the participant    30min Provide breakfast/snacks    30min 1. Basic personal/demographic information

2. Baseline physiological measurements3. Rest

Apply and collect physiological data such as core temperature and heart rate.

  30min Participant adaptation 1. No cooling 2. Inside the chamber3. Sit and rest on a backless chair

  ~30min 1st self-paced running-Participant can adjust the running speed by themselves-Initial running speed = 7km/h, 1% incline-At all times participant has control of the treadmill speed but the treadmill display was masked

1. No cooling 2. Real-time measure of core temperature, skin

temperature, and heart rate.3. Record the time spent, running speed and

distance covered.  4. Stop running when core temperature =38.5 oC

  30min 1st recovery 1. No cooling2. Sit and rest on a backless chair3. Real-time measure of core temperature and

heart rate.  ~30min 2nd self-paced running

-Participant can adjust the running speed by themselves-Initial running speed = 7km/h, 1% incline-At all times participant has control of the treadmill speed but the treadmill display was masked

1. With cooling vast2. Real-time measure of core temperature and

heart rate.3. Record the time spent, running speed and

distance covered. 4. Stop running when core temperature =38.5 oC

  30min 2nd recovery 1. With cooling vast2. Sit and rest on a backless chair3. Real-time measure of core temperature and

heart rate.    Done  

Climatic chamber

Treadmill and data monitor

Treadmill panel (speed display was masked)

Real-time data record

Chamber: 30 oC, 75% RH

Heat stress monitor

Heat stress monitor

Temp and humid monitor inside chamber

EquipmentEquipment

Core Temperature Sensor Calibration

CalibrationDate ID of subject Serial# Calibration# Name of subject ConditionCalibration 28 November #98 275237 41761348 Tang Wing Hung

Paper cup; (ml); 44oC water

5th trial about 30 minutes

Real time CorTemp (oC) Thermometer (oc) Difference20：14 41.69 43.19 1.520：15 42.15 42.7 0.5520：16 41.81 42.19 0.3820：17 41.35 41.71 0.3620：18 40.87 40.8 -0.0720：19 40.44 40.38 -0.0620：20 40.02 39.95 -0.0720：22 39.22 39.17 -0.0520：23 38.85 38.78 -0.0720：24 38.5 38.39 -0.1120：25 38.15 38.09 -0.0620：26 37.78 37.72 -0.0620：27 37.43 37.36 -0.0720：28 37.08 37.03 -0.0520：29 36.42 36.36 -0.0620：32 35.79 35.73 -0.0620：33 35.48 35.42 -0.0620：34 35.19 35.13 -0.0620：35 34.9 34.83 -0.0720：36 34.62 34.56 -0.0620：37 34.34 34.29 -0.0520：38 34.09 34.02 -0.0720：39 33.83 33.77 -0.0620：40 33.59 33.52 -0.0720：41 33.33 33.28 -0.0520：42 33.1 33.05 -0.0520：43 32.87 32.8 -0.0720：44 32.64 32.58 -0.0620：45 32.42 32.36 -0.0620：46 32.2 32.14 -0.0620：47 31.99 31.93 -0.0620：48 31.79 31.73 -0.0620：49 31.6 31.52 -0.0820：50 31.39 31.34 -0.0520：51 31.2 31.14 -0.0620：52 31.01 30.95 -0.0620：53 30.83 30.77 -0.0620：54 30.66 30.59 -0.0720：55 30.47 30.41 -0.0620：56 30.31 30.23 -0.0820：57 30.14 30.08 -0.0620：58 29.97 29.92 -0.05

Preparation Session of

Treadmill Running

Preparation Session of

Treadmill Running

Treadmill RunningTreadmill Running

After Treadmill Running

ControlControlWearing Korean cooling vestWearing Korean cooling vest

Summary of 1st lab test results

30min resting

Core temperature 37.65 37.66 oC

Heart rate79 91.6 bpm

1st running (without cooling vest)

Core temperature 37.66 38.5 oC

Heart rate91.6 180.7 bpm

Duration: 26min 23sec Total distance: 4082m Average power: 136.3W

1st 30min recovery (without cooling vest)

Core temperature 38.5 38.11 oC

Heart rate180.7 112.2 bpm

2nd running (with cooling vest)

Core temperature 38.11 38.5 oC

Heart rate112.2 173.4 bpm

Duration: 32min 20sec Total distance: 4050m Average power: 110.3W

2nd 30min recovery (with cooling vest)

Core temperature 38.5 37.96 oC

Heart rate173.4 106.1 bpm

Comparison during runningDuration Total distance

Without cooling vest 12min 11sec 1866m

With cooling vest 32min 20sec 4050m

38.11 38.5oC

Comparison during runningDuration Total distance

Without cooling vest 12min 11sec 1866m

With cooling vest 32min 20sec 4050m

180.7 bpm

173.4 bpm

Comparison during recoveryDuration Decrease in Core Temp

Without cooling vest 30min 0.39oC

With cooling vest 30min 0.54oC

38.11oC

Pre-running 37.66oC

Comparison during recoveryDuration Decrease in Heart Rate

Without cooling vest 30min 68.5bpm

With cooling vest 30min 67.3bpm

180.7bpm

112.2bpm

173.4bpm

106.1bpm

Pre-running91.6bpm

Index Mean values ± SD RangeNatural wet bulb temperature (℃) 26.09 ± 0.47 24.14 ~ 26.90Dry bulb temperature (℃) 28.85 ± 0.48 25.01 ~ 29.76Globe thermometer temperature (℃) 29.48 ± 0.80 26.01 ~ 30.24Relative humidity (%) 80.67 ± 3.82 74.00 ~ 89.00Wet bulb globe temperature index (In) (℃)

27.08 ± 0.59 24.49 ~ 27.78

Wet bulb globe temperature index (Out) (℃)

27.09 ± 0.49 25.13 ~ 27.72

Heat index 35.44 ± 1.23 30.50 ~ 37.5Wind speed in meter per second (m/s) 0.32 ± 0.09 0.13 ~ 0.47

Environmental Data (Chamber)

ProductivityCalculated using the

formula different

results ask Rey to check

PSI

Real time

19:43:02- 20:08:02Rest (30 min)*

bufferingtime

20:12-50-20:39:13 1st Running (26 min 23 sec)

20:39:13-21:09:131st Recovery (30 min)

bufferingtime

21:10:42-21:43:02 2nd Running (32 min 20 sec)

21:43:02-22:13:022nd Recovery (30 min)

HR#

91.6 　 180.7 112.2 　 173.4 106.1Tc#

37.66 　 38.538.11 (0.39 decrease) 　 38.5 37.96 (0.54 decrease)

PSI 0 　 7.322 2.388 　 6.909 1.635

#:the average of the last 1min.*: The data are available for only 25 min.

Using Del’s data (1st lab test report & HR-Tc Syned) [ignored the abnormal data]

Formula: PSI=5*(HRi-HR0)/(180-HR0)+5*(Tci-Tc0)/(39.5-Tc0) where HR0 and Tc0 are the resting values (the average at ) in the chamber prior to the exercise. HR0=91.6 bmp, Tc0=37.66 oC

PSI (con’t)

Discussion for some issues

Data frequency

Sweat rate• Failed to calculating Sweat rate

Time sequence

Parameters in the formula

Pre-exercise nude body weight (kg) Post-exercise nude body weight (kg)

Fluid intake during exercise (ml)

Urine volume during exercise (ml)

Exercise time (mi)

Parameters in chamber test

Food Fluid Clothing Pre-exercise body weight

Fluid Post-exercise body weight

- - Exercise time (mi)

Stage 1 bread 240 ml 0.32 kg 57.66 kg water 57.42 kg - - 26.38

Stage 2 - water New clothes but wet shorts

57.66 kg water 57.45 kg - - 32.33

Wet shorts? Is it necessary to change a

new uniform？

Is it necessary to weigh the body weight first and

then drink water?

Further issues

• 1. How to detect 38.5 oC? (By Mr. I.K.)

• 2. The interval of CorTemp To change another monitor

• 3. 30 min for rest Clock ?

Thanks