Hot Weather Health and Safety: Planning Before the Heatwave

Every year around this time, the same issues resurface. Heat stress on site. Dehydration for people working outdoors or in warehouses. Fatigue from longer shifts. Drivers struggling with glare and tiredness on the way home. And every year, they catch businesses out again.

The fix is not complicated. It just needs to be planned rather than improvised on the hottest day of the year.

Why hot weather keeps catching employers out

Heat is an unusual workplace hazard because it arrives gradually and then all at once. A run of mild days does not prompt anyone to act. Then the temperature climbs, everyone is already mid-shift, and decisions get made under pressure by people who are themselves too hot to think clearly.

There is also a perception problem. Cold, wet and dark conditions feel like hazards. Sunshine does not. Staff who would never climb a ladder without checking it will happily work through a 30-degree afternoon without a break, because it does not feel like a risk. That is precisely what makes it one.

What the law actually requires

There is no maximum workplace temperature in UK law. That surprises people, and it is often used as a reason to do nothing.

Five things worth doing before the temperature climbs

1. Adjust work patterns during peak heat

Physical work between 11am and 3pm is the obvious candidate for moving. Starting an hour earlier costs very little and removes the worst of the exposure.

2. Make water and shade genuinely accessible

A tap in a site office 200 metres away is technically available. Nobody will use it. Water needs to be where the work is happening.

3. Brief supervisors on the signs of heat stress

Headache, dizziness, cramps, confusion, and the one people miss — someone who has stopped sweating. The point is to catch it early, not after somebody has gone down. Supervisors are best placed to notice, and are often the least briefed.

4. Review PPE

Kit that is perfectly sensible in March becomes a liability in July. Coveralls, respirators and high-vis layers all trap heat. This does not mean removing protection; it means checking whether lighter equivalents exist, and building in more frequent breaks where they do not.

5. Think about the drive home

Fatigue and glare after a hot shift are a genuine risk, and one that sits outside most people’s mental model of workplace safety. If your staff drive for work, it belongs in the assessment.

The paperwork test

Here is a quick way to tell whether your seasonal planning is real or nominal. Look at your hot weather risk assessment. If it is the same document you used last year with the date changed, it is not doing anything.

Conditions change, staff change, and the work changes. A control measure referencing a shaded break area that no longer exists is worse than none at all, because it creates a false record of having addressed the problem. Reviewing it takes an hour. Explaining to an inspector why nobody looked at it takes considerably longer.

None of this needs a big budget

That is the part worth emphasising. Most of what makes a real difference in hot weather costs almost nothing — an earlier start, water in the right place, a five-minute briefing, a break schedule that accounts for the forecast.

What it needs is five minutes of planning before the heatwave, rather than a scramble during it. If your seasonal risk assessment has not been looked at since it was written, that is worth addressing while the weather is still mild.