IAQUK Resources - Temperature
Individuals essentially use two methods to ensure we maintain an optimum
- Thermoregulatory Response
- Autonomic Physiological Response
Achievement of optimum body temperature is achieved firstly by
behavioral response to self regulation of thermal comfort. Such
thermoregulatory responses typically include:
- Modifying clothing insulation
- Altering the environment thermostat
- Opening a window
- Drinking a temperature drink
- Using mechanical aids, such as fans or heater
- Splash water on body to cool down
- Adjust work rate
Autonomic Physiological Response
Where such adjustments are not possible or as effective,
autonomic physiological responses are involuntary employed by the body’s
defense mechanism. These include:
- Our skin vessels dilate in heat to assist with redistributing warm blood
from the core of your body to the body surface to help increase dry heat loss
- We also sweat to facilitate the evaporation of heat loss (conductivity).
Sweating usually begins when the body’s temperature rises above 36.7°C.
When the body temperatue cools, the body responses by
shivering. This is called shivering thermogenesis, when muscle groups
contract and relax in small movements which result in creating warmth by
Thermal Energy Transfer
energy can transfer through an environment from a hot source to a cold source,
using three methods:
is the transfer of heat via substances that are in direct contact with each
other. The better the conduct the more rapidly the heat
will transfer. As an example metal pipes carrying hot water.
moves energy via gases and liquids. As liquid or gas heat, it expands,
causing movement. An example, steam from a hot water, or cold chilled air to
cool a room or refrigerant.
waves traveling through the atmosphere is called radiation. When the electronic waves come in
contact with an object, it transfers its heat. As an example the sun’s solar
methods are relevant when monitoring or risk assessing source of
temperatures and transfer within an environment.
However it is not just the environment that affects
an individual’s core temperature or their perception of thermal comfort.
High levels of carbon dioxide complicate the body’s
ability to self regulate. Carbon dioxide can suppress shivering, it
can cause confusion for an individual to accurately gauge the ambient
temperature, and it can also increase blood flow which consequently raises body
temperature. At high humidity the body is less effective of losing heat through
conductivity (sweating). This is due to the amount of vapors in the
air, reducing evaporation from our skin.
Eating a large meal can increase your core temperature
and cause sweating. This is called diet-induced thermogenesis when
your body has to generate more energy to digest the meal.
Exposure to frequent changes to temperature,
effects the body’s ability to respond, such as sitting near a draft, fans,
ventilation exchanges, solar energy (sunlight) from sitting near windows,
moving around different temperatures within the workplace (outside to indoors).
The pace of your work activity and physical labour required can create core
temperature from energy expelled.
With buildings becoming more energy efficient and the environment controlled mechanically, reducing the control the occupant has over their thermal comfort, often relates to a difficult quest for the facilities management team to find an optimum working condition. Therefore good practices would adopt a comfort working temperature parameter policy for thermal comfort, that is realistic and achievable.
Thermal comfort may be compromised by extrinsic matters, such as during period of power loss, or extreme weather conditions. A continuity plan will assist with direct action to maintain thermal comfort during, such as portable thermal devices, breaks, clothing and access to hot/cold drinks.
Consult with employees about suitability and what is achievable, discuss parameters for temperature ranges and what action employers will take if these parameters are exceeded.
An employer must take reasonable care to identify any foreseeable health or safety hazards, which could harm the employee or other persons in the workplace. The hazards may involve work practices and systems, people, equipment, materials and environment.
Identify the risks
Consult with occupants
Identify potential thermal sources
Identify thermal transfer
Assess the risk
Number of people involved
Vulnerability of people
Work practices and work rate
Type of plant, equipment or materials used
The capability, skill, experience and age of people doing the work
Control the risk
Eliminate or control the risks as reasonably practicable using hierarchy of controls.
Monitor and Review
Monitor and review as required by your risk assessment.
Occupants should be consulted when assessing the potential risks from exposure to hot or cold conditions. Employees must also have input into the risk controls selected.
Factors to consider when risk assessing temperature
within the workplace:
Are there any high or low temperature hot
spots? Are these due to the occupants using fans or
heaters? Has new equipment been installed? Has this interference affected
Are occupants exposed to energy from machinery or
solar energy from windows?
Are the occupants exposed to drafts, ventilation
diffusers? Can you isolate the source or move the occupant?
Is there any difference between floor to ceiling
temperature gradients? The difference should not exceed 3°C.
Are the thermostats functioning and
calibrated? Are they correctly located away from temperature
sources? Do they control the rooms indicated?
Does the air distribute a balance
circulation? Do occupants use fans?
Are there any obstructions to the air circulation,
such as office partitions, cabinets, display stands etc?
Consider the occupants, such as vulnerable people
and individuals health conditions or medication that may influence thermal
Explore the work rate within the environment, could
this influence core body temperature? Are employees working in extreme
temperatures allowed to take suitable breaks? Wear suitable personal
protective clothing? Access to fluid replacement when subject to dehydration?
Are there areas of overcrowding increasing thermal
Are there any complaints, occupational health
referrals or incidents resulting from thermal conditions?
What temperature transfers methods are employed
which may affect the thermal comfort? (uninsulated hot water pipes,
solar energy etc)
Are plant, service lines, walls, floors and roofs
Are extreme thermal sources removed from exhausts
or other sources to outside the building?
Are staff consulted about working
temperatures? Do staff receive training about reporting thermal
Do you employ regular monitoring activities and
document findings? Do you have a competent person to conduct such