1. Heat Stress

2. International Paper Cedar River Mill
Curt Krambeer, Process Team Member
Leon Hospodarsky, Manufacturing Support Team Member

4. What is Heat Stress
Heat stress is defined as a condition in which the total net heat load on your body from internal heat production and external sources exceeds your body’s capacity to cool itself.

6. Why worry about Heat Stress
A report from the U.S. Department of Commerce, states that a conservative estimate of the number of workers in industries where heat stress is a potential safety and health hazard would be 5 to 10 million workers.
The CDC reported that during the period a total of 3442 deaths resulted from exposure to extreme heat.

7. Levels of Heat Stress
Mild or moderate heat stress may be uncomfortable and may affect performance and safety, but it is not usually harmful to your health. When heat stress is more extreme, the possible health effects or heat-related illnesses include:
Heat edema: swelling.
Heat rashes: tiny red spots on the skin, which cause a prickling sensation.
Heat cramps: sharp pains in the muscles.
Heat exhaustion: excessive loss of water and salt.
Heat syncope: fainting.
Heat stroke: the most serious level of heat stress.

8. Heat Exhaustion vs. Heat Stroke
Heat Exhaustion: is caused by excessive loss of water and salt. Symptoms include:
Heavy sweating (Eventually sweating may stop)
Weakness
Dizziness
Nausea
Headache
Muscle cramps
Heat Stroke: (elevated body temperature) is the most serious type of heat illness – life threatening and requires immediate medical attention. It is the worsening of all the heat exhaustion symptoms plus:
Elevated body temperature greater than 41°C (106°F).
Complete or partial loss of consciousness.

9. Personal Factors
Tolerance to heat stress will vary from person to person (think: age, gender, body mass, medical conditions).
An individual’s tolerance to heat will vary from day to day (think: food and liquid intake, sleep, clothing, drug/alcohol use).
At a minimum, heat stress will generally decrease an employee’s judgment and workmanship.

10. Other Factors Affecting Heat Stress
Air Temperatures
What can be measured by a thermometer.
Other sources of heat
Direct sunlight, machinery that generates heat.
Relative Humidity
Moisture in the air. The more moisture in the air the less your body is able to sweat and cool itself.
Moving air (speed) usually cools a person.
Moving air will cool a person as long as the air moving is cooler than the person. (less than 37°C (98.6°F)
Physical Exertion
Moving around or working generates heat.

11. The Body’s Response to Heat
Body works best when it has an internal “core” temperature of 37°C (98.6°F).
During regular day, your body may vary by about 1°C (2°F).
When you work in extreme hot temperatures, your body has to adapt.
Sweat – evaporating sweat cools the body
Increase blood flow to the skin – (radiate away excess heat)

12. Acclimatization
People can adapt to hotter temperatures through a process called “acclimatization.” Acclimatization allows you to work more safely and efficiently. However, becoming acclimated takes time. (4 to 7 working days)
Your body will learn to adapt, sweat more, conserve body salt, and reduce cardiovascular stress.
Work schedules should consider acclimatization needs.

13. Developing a Heat Stress Program
Prevention is your best defense against heat stress.
Planning should include an analysis of work environments and job duties.
Identify methods to limit employees’ exposure to heat.
Education and training of employees.
Evaluate effectiveness of program.

14. Analysis Various ways to measure heat. Thermometer: Air temperature
Heat Index: Temperature + Humidity
WBGT (Wet Bulb Globe Temperature) Index

15. WBGT
Our Heat Stress Team chose to work with the WBGT (Wet Bulb Globe Temperature)
This device monitors a dry bulb sensor that measures ambient temperature; a wet bulb sensor takes into account evaporative cooling, giving an indication of the effects of humidity on an individual; and a globe sensor provides an indication of the radiant heat exposure on an individual due to either direct light or hot objects in an environment.

16. WBGT continued
The team performed studies in each mill during the summer of 2008, gathering information to determine potentially hot locations.
In addition, the team worked with maintenance personnel to study the affects of moving and cooling the air for scheduled jobs.
Data from the studies along with feedback from those working on the jobs was collected.

17. What did we determine?
There are definite hot spots in the mill regardless of the time of year.
Both maintenance and process have jobs that are more susceptible to heat stress regardless of the time of the year.

18. Red Zones
A “Red Zone” was defined as having the capability of being a hot area regardless of the time of year. Those areas marked were:
#1 PM #2 PM
Pulpers – Op. Floor Pulpers – Op. Floor
Saveall Saveall
Dryer section (All) Dryer section (All)
All of OCC Mezzanine from All of OCC Mezzanine from
North Hatchway North. North Hatchway North.
Top side of Machine Top side of Machine

19. Possible Control Methods
Pre-work planning can decrease the chance of heat stress.
Engineering controls (such as AC units).
By using fans, misters, air horn, etc., we can control the environment.
Using cooling PPE can help control body core temperature.
Limiting the amount of exposure time will help.

20. Decision Tree

21. Risk Assessment Card

22. JPSA

23. Fan Maintenance
Exhaust and Cooling Fans are critical to help cool these warm environments
Team members are responsible to write work notifications for any permanent fan that requires attention
Portable fans should be transported to the Shop for repair as necessary
Area Process Owners will maintain fans

24. PPE Options Safety cooling vests Chill cap Chill It bandana
Terry cloth tori band
Sponge tori band

25. Hydration Options Additional water fountains Portable water coolers
Extra bottled water when needed
Gatorade stations
Electrolyte packets
Popsicles

26. Policy Development
Heat stress policy updated to incorporate identified process improvements.
Education and training required for all employees.

27. Education
Symptoms
Recognition
Treatment
Prevention is the key.

28. Training New hire orientation training Yearly refresher training
First responder training
Leadership training

29. Preventing Heat Stress
Know signs/symptoms of heat-related illnesses; monitor yourself and coworkers.
Block out direct sun or other heat sources.
Use cooling fans/air-conditioning; rest regularly.
Drink lots of water; about 1 cup every 15 minutes and electrolyte drinks in moderation.
Wear lightweight, light colored, loose-fitting clothes.
Avoid alcohol, caffeinated drinks, or heavy meals.

30. Scenario – OCC Sump Pump Belt Replacement (in July)
Review Heat Stress Decision Tree
Unplanned job in non - Red Zone
Complete JPSA or Risk Assessment Card
Per the JPSA or Risk Assessment Card consider whether any Heat Stress controls or PPE are necessary
Stay hydrated!

31. Scenario – Removing Dryer Section Pileup (in August)
Review Heat Stress Decision Tree
Unplanned job in Red Zone
Complete Risk Assessment Card
Per the Risk Assessment Card use appropriate Engineering Controls and PPE for Heat Stress
Examples of PPE include cooling vests
Stay hydrated!

32. TIP!
Intense thirst is not a good warning sign of heat stress, an unacclimatized worker may not experience thirst.
If you experience thirst you are already becoming dehydrated!
Prevention is your best defense against heat stress.