Sleep and shift work: how employers can prevent fatigue without monitoring nights

When an organization introduces non-standard hours, it should assess the risks of the jobs concerned and check that its existing prevention measures still fit. That assessment starts from the hours people actually work, not only those in their contracts: starts before 6 a.m., late finishes, quick changeovers between shifts, unplanned call-backs, overtime, time-zone changes and commuting time.

The risk goes beyond comfort. According to INRS, daytime sleep is shorter, more fragmented and less restorative; the resulting sleepiness and loss of alertness can cause accidents, which are more frequent on the commute before a morning shift and after a night shift. So also map the tasks where a drop in alertness could have serious consequences: driving, machinery, lone work.

Involve employees, their representatives, occupational health and operations managers. The collective data you already hold (incidents by time of day, roster changes, overtime) can shed light on the risk, as long as it is never used to profile one person’s health.

Fatigue has many causes, at work and outside it. A sleep disorder calls for a medical assessment. Between the two, a manager’s role is narrow and specific: listen to the signal, make the immediate situation safe if needed, look at what in the work organization might explain it, and refer the person to occupational health.

Drowsiness at the wheel or on a machine calls for an immediate safety response, not a future awareness campaign. The procedure must be known to everyone, non-punitive and applied the same way to all; otherwise nobody will report their own fatigue.

Telling a team whose rosters change every week to “go to bed earlier” or “switch off” shifts the responsibility without touching the cause. The levers that matter sit in the work organization. Among those INRS recommends considering:

• fast rotations that limit consecutive night shifts (two to three at most);
• at least eleven hours off between two shifts, and rest days preferably placed after night shifts;
• morning start times pushed back as far as possible, after 6 a.m.;
• rosters people can plan around, with room to swap shifts with colleagues;
• real breaks, including for a short nap of under twenty minutes;
• a way back to standard hours.

The US National Institute for Occupational Safety and Health (NIOSH) makes similar points in its training on shift work and long hours: keep consecutive night shifts to a minimum on rotating schedules, and give people some control over their schedules. There is no single optimal roster: jobs, individual chronotypes and family constraints differ. INRS stresses voluntary assignment to these schedules and involving employees in decisions about start times, rotation pace and breaks, because acceptance depends on how stable and predictable the rosters are.

On standard hours: the right to disconnect

Sleep is not only a shift-work issue. In France, the right to disconnect is written into the Labor Code to protect rest periods and personal life: it is negotiated with employee representatives or, failing an agreement, set out in a company charter. Whatever the legal framework where you operate, the practice is the same: measure after-hours requests, define what counts as urgent and schedule messages for working hours. A late-night email labeled “no need to reply” quickly becomes an unwritten rule of availability, and INRS notes that technical settings are not enough without looking at workload.

General information still helps: sleep-wake rhythms, light, caffeine, meals, warning signs of drowsiness. Occupational health services are well placed to deliver it, taking each team’s real constraints into account. Hold these sessions during paid working time, at hours night teams can actually attend.

Avoid sleep challenges, individual scores and rewards based on a smartwatch. They are intrusive, hard to interpret and exclude people who cannot or do not want to use health wearables. Sleep data is not trivial either: France’s data protection authority, the CNIL, points out that a measurement becomes health data once, combined with other data, it allows conclusions about a person’s health.

Some employees will need personal support. They should find it with qualified professionals, never through their manager: the CNIL states that employers have no right to hold medical information about their staff. The rules that make such support possible (genuinely voluntary participation despite the employment relationship, aggregated reporting only) are covered in our article on employee health privacy. Before buying any tool that touches sleep, involve your data protection officer, employee representatives and occupational health: under the GDPR, a data protection impact assessment may be required for processing likely to pose a high risk to people.

With MyTwin for employers, the organization chooses which prevention modules to offer. Employees who want to can follow a personal pathway, coordinated by a MyTwin physician or by the company’s own medical team, who interprets results and sets the next steps. The employer only sees aggregated indicators and keeps control of what is truly theirs: how work is organized.

1. Scope. Pick a specific goal: fewer after-hours requests, a safer critical job, more predictable rosters, better support for a night team. “Improve sleep” is too vague to manage.
2. Assess collectively. Review schedules, workload, breaks and incidents; run representative working groups; gather people’s experience without asking for any diagnosis.
3. Change the organization. Test a small number of changes (notice period for roster changes, revised rotation, recovery time, staffing, communication rules) and document what changes.
4. Offer confidential support. Make occupational health and referral routes visible, outside the management line.
5. Evaluate and adjust. Track collective indicators: roster stability, after-hours requests, breaks actually taken, incidents, perceived fatigue collected anonymously. A short-term drop in incidents does not prove on its own that the program works: our guide to measure a workplace health program sets out the method.

What decision-makers should turn down

• claims that a consumer device can detect fatigue with certainty;
• named individual data reported to managers;
• rankings of teams or individuals;
• mandatory sensors, let alone outside working hours;
• recommendations that ignore how work is organized.