Prevention of Heat Stress

Prevention of Heat Stress

Presentation Outline What is heat stress? Body s response to heat stress Why does heat stress occur? Heat stress predisposing factors Effects of heat Prevention Management

Thermoregulation How the body works in preventing heat stress Exercise & physical work produce heat & cause a person to sweat This heat is brought to the body surface by blood vessels (circulation) When sweat evaporates from the skin surface cooling of the body occurs

What is Needed for Efficient Body Cooling The skin must be able to produce the necessary amount of sweat The sweat must be able to evaporate Out in the field evaporation is usually the only cooling method the body has available Sweat rates can be up to 2.5 litres per hour

Why Does Heat Stress Occur The temperature Not drinking enough fluids Unnecessary heavy clothing High levels of humidity No or very little air movement Level of physical activity

Dehydration the importance of fluid replacement If you are thirsty you are already dehydrated Headaches can occur with small fluid loss e.g. 1-2 litres Small levels of dehydration does have a direct impact on your sweat rate Best method of prevention is to drink small amounts regularly - 250ml every 15 minutes when working in direct heat Sweat is 99.9% water so replace it with water

HYDRATION you need to check your pee Dehydrated Getting Dehydrated Drink as much WATER as it takes to keep your urine a pale yellow colour Thirst is NOT a good sign of hydration Have regular frequent drinks of water Urine monitoring is essential, if you have not regularly passed urine you have not drunk enough Hydrated HGR first aid staff can measure hydration through a simple urine test Hydrate today for tomorrow

Sports Drinks There is usually enough salt in a normal diet to replace electrolytes lost by sweating If you work in high temperatures or have a high workload job the use of small amounts of electrolyte replacement drinks may be of benefit Sqwincher etc

Predisposing Factors Inadequate acclimatisation Obesity Existing illness Sleep deprivation Excessive use of alcohol Illicit drugs Medication Dehydration Pre-existing heart condition Age Work level

Heat Stress Heat Rash (prickly heat) is caused by the skin being continuously wet from unevaporated sweat causing itchiness and red skin. Heat Faint occurs when body fluids shift to the skin to cool the body resulting in a drop in blood pressure. Heat Cramps are painful spasms of the muscles that are thought to be caused by a depletion of salts (electrolytes) due to excessive sweating.

Heat Exhaustion Occurs when fluid lost through sweating has not been adequately replaced. Body can continue to produce sweat, but at a lower rate than is necessary to cool it. Feeling hot, flushed Weakness or fatigue Headache Muscle cramps Dizziness Nausea and vomiting Possible fainting Clammy moist skin Pale complexion Confusion

HEATSTROKE Life threatening disorder resulting from the body s inability to cope with excessive heat load. Failure of the heat regulating mechanisms resulting in lack of sweating Hot dry skin Rapidly rising core temperature Rapid pulse Headache Nausea and vomiting Delirium, confusion Convulsions Collapse and coma DEATH

Prevention individual preventative measures Water replacement drink lots of water Avoid excessive alcohol and carbonated drinks Eat regular balanced meals Maintain personal fitness Understand the importance of acclimatisation Wear lightweight breathable clothing that covers the arms and legs Understand the symptoms of heat stress report to first aid immediately if suffering from headache etc Look after your workmates

Prevention Safe work practices Modify the rate at which work is performed take extra breaks Consider your level of acclimatisation Ensure plentiful water is at hand Where required ensure that ventilation is plentiful Rotate work from hot to cool areas if possible Include heat stress in all JSAs and STARs

PREVENTION Supervisory staff shall give consideration to, and where practicable, implement the following measures Re-scheduling of heavy work to cooler times of the day Modifying the rate at which work is performed (do not pressure employees to get work done in a specific time frame) Increase number of rest breaks Rotate staff through heavy jobs Provide shelters and ventilation Ensure plentiful cool water is available encourage employees to undertake programmed drinking Provision of suitable clothing

ACCLIMATISATION The body s improved ability to withstand heat stress after repeated exposures to hot environments Acclimatisation can take between 4 10 days and is usually lost after 28 days When acclimatised to heat you sweat more to cool down and your sweat is more diluted to conserve electrolytes You may need to reduce work load during acclimatisation If you have suffered previous heat related injuries you are more susceptible to further occurrences, this may lead to a longer acclimatisation period

Management of Heat Stress Stop work Move to a cool environment and lay down Loosen clothing Cool by fanning, use shower or water spray, soak clothing, place in water bath or apply wrapped ice in packs to groins and armpits Give water to replace lost fluid CONTACT MEDICS

Treatment for Heat Stroke and Heat Exhaustion If Heat Exhaustion or Heat Stroke are Suspected Immediately seek medical assistance THIS IS A MEDICAL EMERGENCY Danger Response Send for help Airway Breathing Compressions Get the person out of the heat and rapidly COOL them by spraying with water and fanning down or by using ice packs

No-one wants this!

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