1. Heat stress & awareness

2. What is heat stress?
Heat stress is a general term which describes a variety of symptoms produced when the human body is exposed to a combination of heat and work which interferes with the body’s ability to dissipate the heat energy.
Common, early, but often subtle signs of heat stress include:-
Headache
Disorientation / confusion
Impatience / irritability
Prone to making errors
Dry mouth lips (already 20% dehydrated at this point)
NOTE: heat stress can develop over the day and manifest in the afternoon
General background information:-
Normal inner core body temperature = 37 degrees Celsius
Above 38 degrees = heat stress
40 degrees Celsius = life threatening / medical emergency
Body is comprised of 75% water, brain 85% water

3. How the body works to cool itself….
Brain signals to cool the body
Heat source
Main form of cooling is via sweating onto the skin which then evaporates resulting in cooling
THIS PROCESS CAN DEVELOP QUICKLY
If untreated this will result in death
Increased sweating reduces amount of salt and water in the body resulting in dehydration
Eventually a state is reached where the body is unable to cool itself sufficiently and the core temperature begins to rise
BACKGROUND INFORMATION FOR PRESENTERS;
Heat stress can develop quickly – if you think you or one of your mates is suffering the effects tell your supervisor & seek first aid or medical assistance depending on your level of competence to act and the severity of the symptoms
The process:-
1. Brain signals to cool body – main way is by sweating (sweat to skin, evaporates and cools)
2. Increased sweating reduces water and salt in body = dehydration
3. If can’t cool sufficiently – core temperature increases = changes to body and brain function
4. If untreated, this will result in death
This results in changes to body and brain function

4. What causes heat stress?
Environmental Factors
Personal Factors
High temperature levels
Type of clothing worn
High humidity
Level of acclimatisation of workforce
Returning from R & R
New employees from countries with cooler climates
Low levels of air movement
State of hydration
Heat sources in the area:-
Heat generating / radiating equipment, appliances or structures
Health & fitness:-
Infection / fever
Diarrhoea / vomiting
Medication use
Obesity
Level of physical fitness
Sunburnt
Level & type of physical activity
Excessive consumption of alcohol
General background information / examples for presenter:-
Examples of types of physical activities that can cause heat stress:
Hot work
Working in confined spaces
working on roofs or in open areas exposed to sunlight / radiation
Examples of PPE that may result in heat stress:
Coveralls
Respirators

5. Different types of heat stress….
There are a number of different forms of heat stress that differ in their level of severity:-
HEAT STROKE
Heat Exhaustion
Heat Collapse
Heat Cramps
Heat Rash
Heat Fatigue
BACKGROUND INFORMATION FOR PRESENTER:-
Heat fatigue
Impaired performance
Lapsed concentration
Heat rash
Often termed “prickly heat”
Skin rash caused by excess sweating or the skin being wet with sweat
Usually resolved with acclimatisation or removal from heat
Heat cramps
Painful muscle cramps of the limbs and / or abdomen, muscle twitching, tingling or pins and needles in the hands and feet
May experience fatigue / nausea
Salt and potassium help muscles contract and when salt levels become imbalanced due to continual perspiration or lack of water consumption (causing build up of salt) or a low salt intake (causing the opposite) the muscle contractions no longer occur normally
Heat collapse
Person collapses or faints due to reduced blood flow to the head
When the body heats up the blood flows to the outer extremities / skin to cool the body – away from the brain
Often rapid and unpredictable
Heat exhaustion
Heat Stroke
Most severe form of heat stress
Brain loses the ability to regulate the body’s temperature
Body temperature rises to a critical, life threatening level (i.e.. 40 degrees Celsius +)
Can quickly result in death

6. First aid for less severe heat stress conditions….
If heat fatigue, heat cramps or heat collapse is suspected:-
Rest casualty in cool, shaded place
Loosen / remove clothing
Cool with wet cloth under arm pits, behind knees
Direct a fan over the casualty
Give cool (but not ice cold water) to drink
Call for medic
…. BUT WHAT IF THE SIGNS ARE MORE
SERIOUS?......

7. Heat exhaustion vs. heat stroke – signs
Dry, hot skin
educed sweating
Rapidly rising temperature
Pupils constricted
Rapid pulse
Convulsions
Collapse & coma
Life threatening
HEAT EXHAUSTION
Moist, clammy skin
Increased sweating
Normal or subnormal temperature
Pupils dilated
Rapid breathing (panting)
Muscle cramps
Pale complexion
COMMON TO BOTH
Nausea & vomiting
Confusion
Headache
Dizziness
Weakness or fatigue

8. Heat exhaustion vs. heat stroke – management
DRABC
Move to a cool place
Loosen tight clothing
Apply cold packs / ice to areas with large blood vessels
Cover with wet sheet and fan
Do not give fluids unless casualty is conscious
SEEK IMMEDIATE EMERGENCY MEDICAL ASSISTANCE
HEAT EXHAUSTION
Move to a cool place
Offer sips of cool water if the casualty is conscious
Call for medical assistance

9. Methods of prevention....
Remove heat source, e.g. Shut down heat generating equipment
Reschedule work to a cooler time of the day
Increase air movement, e.g. fans
Erect structure or heat shields around hot components
Slip-slop-slap
Erect shade shelters or work in shaded areas if possible
Training / education
Use of appropriate PPE, e.g. wide brims over hard hats
Note risks and controls in JHA’s
Employee rotation
Suitable work pace
Be aware of location of nearest potable water
Take regular breaks in shade or air conditioned crib rooms
YOU
Aware of physical limitations
Be alert to subtle symptoms in you and workmates
Raise any concerns with supervisor – if feel unwell
Be aware of first aid for heat stress
Hydrate – ml of water at frequent intervals lost body fluid in hot conditions can be as high as 1-2 litres of water an hour
Avoid alcohol / caffeinated drinks – lose even more water / salt
Eat light, cool lunch – hot, heavy meals can reduce your ability to release heat
Apply sunburn cream to all exposed skin areas

10. What more can you do?
Be aware of your own physical limitations and general health / fitness status
Be alert to subtle symptoms in you and your workmates
Raise any concerns or feelings of ill health with your supervisor
Be aware of first aid for heat stress
Hydrate – drink ml of water at frequent intervals i.e. 15 mins (lost body fluid in hot conditions can be as high as 1-2 litres of water an hour)
Avoid alcohol / caffeinated drinks – you will lose even more water / salt
Eat light, cool lunches or snacks – hot, heavy meals or snacks can reduce your ability to release heat
Apply sunburn cream to all exposed skin areas – burnt skin will hold in heat
Give yourself time to acclimatise – whether you are back from a short break or are completely new to conditions
BACKGROUND INFORMATION FOR PRESENTERS:
Acclimatisation – gradually increasing the amount of time you spend working in a hot environment.
It takes about 1-2 weeks for the body to adjust to heat
Acclimatisation is quickly lost – if you are away for a period of 14 days for example

11. hydration Monitor the colour of your urine
The darker coloured your urine, the more you need to drink
This is quite a late sign showing that you are already dehydrated
Drink regularly in small amounts rather than waiting until you are thirsty
Drink water before you commence work and continue to drink
Reduce your intake of caffeine and alcohol (e.g. Red Bull, coffee, beer etc.)
Drink cool rather than cold fluids – cold fluids can cause stomach cramps

12. IN Summary
Working in hot environments is a common element of working in Australia….
TAKE THE TIME TO STOP!
Consider the risks –
CONTROL THEM!
Lets all go home safely every day

13. Do you have any questions for me?