Can i refuse to go to work if it's too hot?

Working in extreme heat poses real health risks from dehydration to heatstroke. But can you legally refuse to show up? Here's what employees and employers need to know.

As summers grow increasingly extreme, heat-related risks at work are no longer exceptional events they're a recurring occupational hazard.

Between 14% and 36% of workers are particularly exposed to high temperatures, especially those in construction, agriculture, and outdoor roles. According to occupational health experts, heat becomes a genuine risk above 30°C for sedentary work, and above 28°C for physically demanding tasks.

So what happens when temperatures soar and you're expected to show up? Can you refuse to go to work if it's too hot?

Can i legally refuse to work because of the heat?

This is one of the most commonly searched questions during heatwaves and the answer is nuanced.

There is no legal maximum temperature above which employees are automatically entitled to stop working. No specific temperature threshold triggers an automatic right to refuse work in most countries. The diversity of work environments from foundries to offices, from construction sites to cold storage facilities makes a single threshold impractical.

However, this does not mean employers can ignore the heat. Employees do have the right to work in a safe environment, and employers have a legal duty of care to protect their health. If working conditions pose a serious and imminent danger to health and safety, employees may have grounds to refuse work but this is a high bar and should not be taken lightly.

In practice, the right approach is to raise concerns with your employer or health and safety representative first, rather than walking off site unilaterally. Doing so without following proper procedures could expose you to disciplinary action, even if your concerns are legitimate.

What are employers' obligations in hot weather?

Employers are required to anticipate, assess, and mitigate heat-related risks. This means monitoring weather alerts, evaluating which roles and workers are most exposed, and taking action before conditions become dangerous.

General measures that employers should put in place include:

• Ensuring adequate ventilation and air circulation in workspaces
• Reinforcing air conditioning where available
• Providing free access to cool, fresh drinking water near workstations
• Adapting work schedules scheduling the most physically demanding tasks during cooler parts of the day (early morning or late afternoon)
• Updating workplace risk assessments to include heat as a documented hazard

For outdoor and construction workers, requirements are more stringent: at least 3 litres of water per person per day, appropriate sun-protective clothing and equipment, and access to shaded rest areas.

Employers must also pay particular attention to vulnerable workers: pregnant employees, those with chronic health conditions or disabilities, and older workers are at significantly greater risk and may require individual risk assessments and tailored protective measures.

Health Risks of Working in Excessive Heat

Heat is not just uncomfortable; it is a genuine medical hazard. The main heat-related conditions workers may face include:

Heatstroke, a medical emergency. The body's temperature regulation fails, leading to a dangerously high body temperature, hot and dry skin, confusion, nausea, and potentially loss of consciousness.

Heat exhaustion, characterised by heavy sweating, fatigue, dizziness, headaches, and nausea. If not addressed, it can escalate to heatstroke.

 Dehydration ,excessive fluid loss that impairs concentration, causes headaches, and increases the risk of errors and accidents.

Heat cramps, painful muscle cramps caused by salt and fluid loss through perspiration.

Beyond the direct health impacts, heat also significantly affects performance and safety. It reduces concentration and increases the likelihood of mistakes a particularly serious concern for lone workers, those operating machinery, or those working at height.

Practical measures to protect workers during heatwaves

Effective heat management at work is about prevention and adaptation. Here is what good practice looks like:

Adapt working hours: Schedule physically demanding tasks for the coolest parts of the day. Where possible, consider temporary shift adjustments during extreme heat alerts.

Create shaded, ventilated rest areas: Workers,especially those outdoors, must be able to take breaks in environments that allow their core temperature to recover.

Prioritise hydration: Make cool drinking water easily accessible at or near every workstation. Remind workers not to wait until they feel thirsty by that point, dehydration has already begun.

Adapt clothing and equipmen: Lightweight, loose-fitting, light-coloured clothing supports thermoregulation. For outdoor workers, sun-protective hats, sunglasses, and sunscreen are essential.

Equip lone workers appropriately: Workers operating in isolation, whether on construction sites, in agricultural fields, or on service routes, face heightened risk during heatwaves. If a lone worker experiences heat exhaustion or loses consciousness, there may be no one nearby to call for help. Providing a dedicated lone worker alarm device is a critical safety measure for these situations.

Train and inform your teams: Every employee should be able to recognise the early signs of heat-related illness and know the emergency procedures. This is not optional, it is part of the employer's legal duty of care.

A special note on lone workers in the heat

Lone workers deserve particular attention during extreme heat events. Whether they work outdoors alone, travel between sites, or operate in confined environments, they face the same physiological risks as any other worker but without colleagues nearby to notice warning signs or call for help.

For these workers, a lone worker protection device that can detect a fall or loss of movement and automatically trigger an alert is not just a regulatory compliance tool it can be the difference between a timely rescue and a tragedy.

What you need to remember

• There is no legal maximum working temperature that gives employees an automatic right to refuse work but employers must still keep conditions safe.
• Employers have a duty of care to assess heat risks, anticipate heatwaves, and implement protective measures.
•  Heat-related illnesses heatstroke, heat exhaustion, dehydration, and cramps — are genuine occupational hazards with serious consequences.
• Vulnerable workers (pregnant employees, people with chronic conditions or disabilities) require specific attention and tailored risk assessments.
• Lone workers need additional protection, including appropriate alarm devices, to ensure someone can respond if they are incapacitated by heat.
• If you believe working conditions pose an immediate and serious risk to your health, raise it with your manager or health and safety representative before taking unilateral action.

Ensuring the safety of your isolated workers during heatwaves means equipping them with the right tools to call for help when they need it.