Irish health and safety rules do not prescribe a general maximum workplace temperature. That is correct, but incomplete. The absence of a single upper limit does not allow an employer to ignore excessive heat. Irish health and safety law requires employers to assess the actual risk and take reasonably practicable steps to protect employees.

Is there a legal maximum workplace temperature?
Regulation 7 of the Safety, Health and Welfare at Work (General Application) Regulations 2007 requires the temperature in rooms containing workstations to be appropriate, having regard to the working methods used and the physical demands placed on employees.

The Regulations set minimum temperatures, so far as reasonably practicable, of 17.5°C for sedentary office work and 16°C for other sedentary work after the first hour. They also require a means of measuring temperature in indoor workplaces and require employers to avoid the excessive effects of sunlight through windows, skylights and glass partitions.
They do not prescribe a maximum. There is therefore no single reading at which every workplace must automatically close. Humidity, air movement, physical exertion, protective clothing, duration of exposure and individual vulnerability may all be relevant. A temperature tolerated in a ventilated office may create a very different risk for someone doing strenuous work or wearing heavy personal protective equipment.

What must an employer do during extreme heat?
Section 8 of the Safety, Health and Welfare at Work Act 2005 requires every employer, so far as is reasonably practicable, to ensure employees’ safety, health and welfare at work. Section 19 requires the employer to identify hazards, assess the risks and retain a written risk assessment. The assessment must be reviewed where circumstances change or there is reason to believe it is no longer valid.

Extreme heat should therefore be managed as a workplace risk, not dismissed as personal discomfort. Depending on the workplace, reasonable measures may include:
•    access to cool drinking water and additional hydration breaks;
•    more frequent rest breaks in a cooler or shaded area;
•    rescheduling strenuous work to cooler parts of the day;
•    rotating employees or reducing the duration of exposure;
•    improving ventilation, shading or cooling where appropriate;
•    temporarily relocating work or permitting remote work where practical; and
•    relaxing dress requirements without compromising safety, hygiene or required PPE.

An employer is not automatically required to install air conditioning. Equally, doing nothing simply because there is no statutory maximum is unlikely to be an adequate response.

Outdoor work: heat and UV are separate risks
Outdoor employees face both heat-related risks and ultraviolet radiation. A day may carry a significant UV risk even where the air temperature does not feel extreme or the sky is overcast.
The Health and Safety Authority’s 2026 Sun Exposure Campaign combines awareness activity with targeted inspections. Inspectors are considering whether employers have included UV exposure in risk assessments, reduced exposure during peak periods and provided suitable information, training and protective measures.
The HSA advises protective measures when the UV Index is 3 or above, particularly between 11am and 3pm. Measures may include planning work outside peak periods, access to shade and water, job rotation, covering clothing, suitable eye protection and broad-spectrum SPF 30+ sunscreen.

Can an employee raise a complaint?
Yes. Employees have a statutory right to make representations to and consult their employer on safety, health and welfare matters. A concern may be raised with a manager, HR, a safety representative or a safety committee.
Section 27 of the 2005 Act protects employees against penalisation for making a safety complaint or representation to their employer, safety representative or the HSA. Penalisation can include dismissal, disciplinary action, demotion, reduced wages, altered hours, intimidation or other detrimental treatment.

Employees should raise concerns promptly and specifically. Useful details include the location and time, the work being performed, any symptoms experienced, the availability of water or ventilation, difficulties caused by PPE and any relevant medical vulnerability.

Can an employee refuse to work?
There is no general right to leave work merely because the workplace is uncomfortably hot. The statutory protection for stopping work applies in more serious circumstances.

Section 11 requires an employer, save in exceptional cases, not to require employees to carry out or resume work where a serious and imminent danger remains. Section 27 protects an employee who, in circumstances they reasonably believe involve serious and imminent danger which they could not reasonably have been expected to avert, leaves or refuses to return while the danger persists, or takes appropriate steps to protect themselves or others.

This is a fact-sensitive and relatively high threshold. It is not an automatic ‘heatwave right to walk out’. Where possible, an employee should report the danger immediately and allow the employer to assess and control it. An employer should not treat a heat-related concern as a disciplinary matter without first carrying out a genuine assessment.

Is there a right to work from home?
There is no automatic right to work remotely because of hot weather. Irish law provides a statutory framework for requesting remote working, not a direct right to obtain it.

A temporary home-working arrangement, altered location or flexible start time may nevertheless be a sensible control where the role permits it. Remote work is one possible response, not a universal heat entitlement.

What about vulnerable employees?
A general heat plan may not be sufficient for every employee.

Once an employer has been notified that an employee is pregnant, post-natal or breastfeeding, specific risk-assessment duties may arise. HSA guidance notes that pregnant employees tolerate heat less well and may be more susceptible to heat stress and fainting. Access to water, rest facilities, adjusted duties or reduced exposure may be required depending on the assessment.

An employee with a disability or medical condition that makes heat exposure particularly difficult may also require appropriate measures under the Employment Equality Acts, unless those measures would impose a disproportionate burden on the employer.

Possible measures may include additional breaks, altered hours, a cooler workstation, modified duties or temporary remote work. Medical information should be handled confidentially, with occupational-health advice obtained where necessary.

A practical approach for employees and HR

A sensible heat response should:
1.    monitor weather, indoor temperatures and the UV Index;
2.    review the risk assessment before conditions become extreme;
3.    consult employees and safety representatives;
4.    introduce proportionate controls and communicate them clearly; and
5.    record complaints, decisions, measures taken and any heat-related illness or incident.

Employees’ rights during extreme temperatures are not tied to one thermometer reading. The central question is whether the employer identified the actual risk, listened to concerns and took reasonably practicable steps to protect health.

A prepared employer will deal with heat before discomfort becomes illness, absence or a workplace incident.
This article is provided for general information only and does not constitute legal advice.

Dalippe Lalloo is the Principal Solicitor of Lalloo Solicitors, a Dublin firm advising on personal injury and litigation matters. He publishes practical information on Irish personal injury law and workplace accidents through https://www.injured.ie