12.0 Temperature extremes

12.1 Introduction to managing extreme temperature risks

This section offers guidance for persons conducting a business or undertaking (PCBUs) on managing the risks to road and roadside workers of working in extreme temperatures.

The outdoor nature of most road and roadside work means road and roadside workers are particularly vulnerable to the effects of working in extreme temperatures.

12.2 Working in extreme heat

Working in extremely hot environments can put workers’ bodies under stress.

If their bodies have to work too hard to stay cool, it can cause heat-related illness and injuries. These can be fatal if ignored.

Heat-related illness and injuries are a risk, especially when working outdoors in summer or in high humidity, or when exposed to radiant heat.

High body temperatures that can cause harm to workers can occur:

in the summer months
in humid environments
during highly physical activities (such as manual rubbish/recycling bin collection, manual excavation, asphalt laying, and roadside gardening)
when warm or heavy clothing is being worn, including personal protective equipment (PPE)
when working near a source of radiant heat. For example:
- near machinery or generators
- during asphalt or emulsion application
- standing on hot road surfaces.

Control measures for work in extreme heat

While it may not be possible to eliminate extreme heat in the outdoor environment, there are steps that can be taken to minimise the effects of working in extreme heat. For example, by:

replacing heat-producing plant with plant that produces less heat
insulating heat-producing plant or use heat screens to reduce radiant heat
using mechanical aids to reduce worker effort
making sure vehicle and mobile plant cabs have air conditioning
providing protection from the sun while working
scheduling work for cooler times of the day or year
frequently rotating workers on tasks
allowing extra rest breaks and providing climate-controlled rest facilities away from the heat and sun
educating workers on the importance of staying hydrated, making cool drinks available at all times, and encouraging them to drink water at the beginning and end of the day
encouraging self-paced work where possible
making sure workers are acclimatised to the conditions
avoiding putting workers with pre-existing medical conditions that may make them susceptible to heat stress in jobs where they will be exposed to extreme heat
making sure PPE is as light as possible and breathable (without compromising its protective function). For more information, see Section 27.5: Make sure PPE does not create new risks
training workers on how to identify signs and symptoms of heat-related illness in themselves and their workmates. For more information, see Working safely in extreme temperatures

Provide PPE for working in extreme heat

PPE can help protect workers against the effects of extreme heat by shielding workers from a hot environment or radiant heat source (such as when laying asphalt). Examples of PPE include:

heat-reflective clothing
face shields
sunhats
heat-resistant footwear.

Sweating is the body’s main way of keeping cool. Make sure that, where possible, PPE and uniforms are made from light, breathable materials so workers can sweat freely.

12.3 Working in extreme cold

Working in extremely cold environments can put workers’ bodies under stress.

If their bodies have to work too hard to stay warm, this can cause cold-related illness and injuries which can lead to permanent tissue damage and death.

Low temperatures can occur:

in wet conditions (being damp or wet can significantly increase the rate a body cools)
winter conditions (frost or snow)
at night (outside temperatures drop even further at night)
in windy conditions (high winds can amplify the effects of cold)
in alpine regions
in open vehicles.

Control measures for work in extreme cold

While it may not be possible to eliminate extreme cold in the outdoor environment, you can take steps to minimise the effects of working in extreme cold conditions. For example:

replacing existing plant with plant that is designed with built-in protection against cold injuries (such as thermally-insulated handles and heated operator cabs)
where possible, scheduling work for warmer times of the day or year
allowing extra breaks for warming up or rotating workers more often when they are exposed to cold conditions
encouraging self-paced work where possible
making sure workers are acclimatised to the conditions
avoiding putting workers with pre-existing medical conditions that may make them susceptible to cold stress in jobs where they will be exposed to extreme cold
providing climate-controlled shelter away from wind and rain during breaks
providing specialised protective clothing that protects from cold, wind, and water
providing drying facilities so wet or damp clothing and PPE can be dried during breaks and between shifts
training workers on how to identify signs and symptoms of cold-related illness in themselves and their workmates. For more information, see Working safely in extreme temperatures

Provide PPE for working in extreme cold

You should provide specialised PPE, such as thermal and weather-proof clothing, that protects workers from cold, wind, and water.

Workers should wear layered clothing to maximise insulation and allow them to add or remove layers to keep comfortable when changing environments.

Clothing should be made of materials that provide good insulation and waterproofing (where required) but are still breathable.

12.4 Monitoring for extreme temperatures

If your workers are being exposed to extreme temperatures while working, you may need to get an assessment done to determine if they are at an elevated risk of developing heat- or cold-related illness or injury.

You may need to add monitoring for extreme hot or cold exposure, and signs and symptoms of heat- or cold-related illness or injury to your health monitoring programme.

For detailed information on exposure and health monitoring for extreme temperatures, see Working safely in extreme temperatures