Heat decree 2025: new employer obligations and air conditioning

After the historic June 2026 heatwave, the issue is no longer taboo: heat at work is a professional risk in its own right. Decree no. 2025-482 of 27 May 2025, known as the "heat decree", significantly strengthens employer obligations. Here is what you need to know, and how office air conditioning becomes a key compliance lever.

Why this decree is a game changer

France experienced heatwaves of unprecedented scale in 2026: 43.8 °C in Saintes on 24 June, 72 départements on red alert in less than a week, and more than 6,300 hospitalisations in two weeks. In this context, heat exposure is no longer a one-off inconvenience: it is a major health risk, with a human cost (heat strokes, dehydration, accidents) and an economic cost (absenteeism, lost productivity, sick leave).

Decree no. 2025-482 of 27 May 2025, adopted pursuant to Articles L. 4121-1 et seq. of the French Labour Code, expands and clarifies the obligation to prevent risks linked to thermal environments. It follows on from ANSES recommendations and the national heatwave plan, while providing an enforceable framework for employers.

What the decree actually says

The text rests on a simple principle set out in Article L. 4121-1 of the Labour Code: the employer must take all necessary measures to preserve the physical and mental health of workers. In practice, the decree introduces or consolidates six obligations.

1. Integrate heat risk into the Single Risk Assessment Document (DUERP)

The Document Unique d'Évaluation des Risques Professionnels (single risk assessment document) must now include a dedicated section on heatwaves: exposed workstations (outdoor work, workshops, kitchens, warehouses), expected frequency, severity, and prevention measures. This integration is not a mere formality: in the event of an accident, its absence is an adverse element in a labour inspection or judicial investigation.

2. Adapt workstations and working hours

The employer must reorganise work during heat episodes:

• Shift physically demanding tasks to early morning or late afternoon.
• Increase the frequency and duration of breaks.
• Set up or create shaded, cool rest areas.
• Reduce the pace for exposed jobs (manual handling, work in the sun, ovens, kitchens).

3. Provide cool drinking water

The decree specifies that the employer must provide cool drinking water in sufficient quantity, close to workstations. The recommended amount is at least 1.5 L per employee per day during heatwaves — which often requires installing extra water points, refrigerated fountains or bottled water.

4. Keep indoor temperatures bearable

This is where air conditioning comes in. Without imposing a single numerical threshold (the decree refers to ANSES and INRS recommendations), the employer must show that all available means have been deployed to keep premises at a temperature compatible with the activity. In practice, this means:

• Blinds, sun-shading and natural ventilation to limit solar gains.
• Air circulators for high-volume premises.
• Efficient, well-maintained air conditioning for offices, shops, practices and open spaces.

5. Inform and train employees

The decree makes it compulsory to inform and train employees about heat-related risks: warning signs (cramps, headaches, dizziness), first-aid gestures, hydration, suitable clothing. A heat referent can be appointed in companies with more than 50 employees.

6. Anticipate peaks through monitoring and an action plan

The employer must set up meteorological monitoring (Météo-France, heatwave alerts) and trigger a graduated action plan depending on the alert level (yellow, orange, red).

Office air conditioning: a compliance lever, not a comfort feature

For employers in the Paris region, the challenge is concrete: having a reliable, efficient and well-maintained air conditioning installation before summer. A poorly adjusted or clogged AC does not cool properly, consumes more, and breaks down at the worst time — exactly the scenario the decree aims to prevent.

Which installation for which premises?

The technical choice depends on the nature of the premises and how they are used. The main options are:

• Multi-split systems: ideal for small offices and practices, with room-by-room control.
• Ducted systems: discreet and even, perfect for open spaces and shops.
• VRF (variable refrigerant flow): the solution for tertiary buildings, with centralised management of many indoor units.

Correct sizing and installation quality are essential: an undersized AC cannot hold the temperature during a peak, an oversized AC wastes energy and creates short cycles. To dig deeper, see our guide to choosing the right air conditioner and our article on air conditioning for offices and businesses.

Maintenance: the sine qua non

An air conditioner that is not maintained can lose 20 to 30 % of its efficiency in a single season. Equipment maintenance is not only good practice: it is regulated by law (refrigerant leak-tightness check beyond certain thresholds, periodic inspection for equipment over 12 kW). The full picture in our article on mandatory air conditioning maintenance in 2026.

Beyond AC: ventilation and summer comfort

The heat decree is not just about installing air conditioners. A comprehensive approach to summer comfort also includes:

• Mechanical ventilation (VMC) to renew air without overconsumption: see our article on VMC in summer and heatwaves.
• Reversible heat pumps, which cool in summer and heat in winter, with excellent energy efficiency: our article on the air-to-air reversible heat pump.
• Daily settings to balance comfort with energy sobriety: how to set your air conditioning properly.

How Proclimo supports employers in the Paris region

Proclimo supports businesses, shops, practices and office managers in the Paris region in their compliance with the heat decree:

• Thermal study and audit of your premises to size the most suitable installation.
• Installation by certified refrigeration technicians, in compliance with best practices and the F-Gas regulation.
• Preventive maintenance contracts with priority intervention in case of breakdown, even during heatwaves.
• Advice on work organisation (layout, cool areas, signage) in connection with your DUERP.

Are you an employer in the Paris region and want to prepare for next summer? Request a free assessment or book an appointment with one of our technicians. To go further, discover our services dedicated to businesses and our professional installation offering.