Working Safely in Hot Weather: Practical Advice for Construction Sites This Summer

This week's heatwave has been a welcome change for many, but for people working in construction, it brings its own challenges.

Anyone who's spent a day on site during temperatures in the high twenties or thirties knows just how draining it can be. Long hours in direct sunlight, physically demanding work and wearing full PPE all take their toll, and it's often the hottest part of the afternoon when concentration starts to dip.

Most people know the basics: drink plenty of water, wear sun cream and take breaks where you can. But staying safe on site during hot weather goes much further than that. A bit of forward planning, knowing how your body reacts to the heat and making a few simple changes to the way work is organised can make a real difference.

Whether you're managing a project, supervising a gang or working on the tools yourself, here are some practical ways to stay safe and productive while temperatures remain high.

Don't Just Drink Water

One of the biggest misconceptions during hot weather is that drinking more water is enough.

When you're working hard, your body loses more than just fluid. Sweating also removes essential salts and minerals including sodium, potassium and magnesium. These electrolytes help regulate muscle function, nerve signals and hydration levels.

Replacing these minerals can help reduce muscle cramps, fatigue and headaches during prolonged periods of hot weather. An electrolyte tablet added to a bottle of water once or twice during a long shift is often more beneficial than drinking litres of plain water alone.

A useful way of checking your hydration is to look at the colour of your urine. Pale straw is generally a sign you're well hydrated, while darker yellow suggests you need to increase your fluid intake. Waiting until you feel thirsty usually means you're already becoming dehydrated.

Start Hydrating Before Your Shift

Hydration begins long before you arrive on site.

If high temperatures are forecast, drink plenty of fluids the evening before and aim to drink around half a litre of water before leaving home. Starting the day hydrated is far easier than trying to catch up once you're already working in the heat.

Alcohol the night before and excessive caffeine first thing in the morning can both contribute to dehydration, so it's worth bearing that in mind during warmer periods.

Plan Work Around the Forecast

Experienced site managers don't just plan around deliveries and subcontractors. They plan around the weather.

Most weather forecasts now provide hourly temperatures and UV levels several days in advance. If temperatures are expected to peak between 1pm and 4pm, it makes sense to schedule the most physically demanding activities earlier in the day wherever possible.

Bricklaying, roofing, concrete works, steel fixing, heavy lifting and groundworks can often be completed during the cooler morning hours. Less demanding tasks such as snagging, inspections, meetings, setting out or paperwork can then be carried out during the hottest part of the afternoon.

Making small adjustments to the programme can improve both productivity and safety.

Remember That Surfaces Get Hotter Than the Air

Air temperature only tells part of the story.

Metal scaffolding, handrails, excavator controls, telehandlers and even power tools left in direct sunlight can become significantly hotter than the surrounding air.

Plant cabs can also reach temperatures well above 40°C if left closed in full sun.

Where possible, allow machinery to cool, wear suitable gloves when handling hot equipment and ventilate enclosed cabs before starting work.

PPE Still Matters

When temperatures rise, it can be tempting to loosen or remove PPE to stay comfortable.

Doing so creates a far greater risk than the heat itself.

Instead, look at ways of making PPE more comfortable. Moisture-wicking base layers, lightweight high visibility clothing, cooling neck towels and hard hat sun shades can all make a noticeable difference without compromising safety.

If clothing becomes soaked with sweat, changing into a dry shirt during lunch can also help your body regulate its temperature more effectively.

Heat Affects More Than People

Hot weather doesn't just put pressure on the workforce.

It can also affect materials and equipment across site.

Concrete may cure faster than planned, adhesives and sealants can become difficult to work with, paints may dry too quickly and batteries in cordless tools often lose efficiency in extreme temperatures.

Allowing for these factors when programming work can prevent unnecessary delays and expensive remedial work.

Eat to Maintain Energy

Heavy meals can leave you feeling sluggish during hot weather because your body uses additional energy during digestion.

Lighter meals containing lean protein, fruit and slow-release carbohydrates are generally a better option for maintaining energy throughout the day.

Fruit such as watermelon, oranges and grapes also contributes towards hydration while providing valuable vitamins and minerals.

Look Out for Your Colleagues

One of the simplest safety measures is often the most effective.

Heat exhaustion doesn't always develop gradually. Someone who seemed fine an hour ago may suddenly become dizzy, confused or unusually tired.

Keep an eye on those around you, particularly apprentices, new starters and anyone returning after time away from work, as they may not yet have adapted to working in warmer conditions.

If someone begins to show signs of heat exhaustion, move them somewhere cool, encourage them to drink fluids and seek medical assistance if symptoms become severe or fail to improve.

Don't Forget About Sun Exposure

Construction workers spend thousands of hours outside over the course of their careers.

Repeated exposure to ultraviolet radiation significantly increases the risk of skin cancer, even on cloudy days.

Applying SPF30 or higher before work starts, wearing UV-protective safety glasses where appropriate and covering exposed skin wherever practical should all become part of the daily routine during the summer months.

Small Changes Make a Big Difference

Working safely during hot weather isn't about stopping work. It's about working smarter.

Planning physically demanding tasks around the forecast, encouraging proper hydration, providing regular breaks in shaded welfare areas and making sure everyone knows the signs of heat exhaustion can dramatically reduce the risk of incidents on site.

As temperatures continue to rise during the summer months, heat should be treated like any other workplace hazard. With the right preparation and a bit of common sense, construction projects can continue safely without compromising the wellbeing of the people delivering them.

At Approach Personnel, we work with construction professionals across the UK every day. Whether you're managing a major project or working on the tools, taking a few extra precautions during periods of hot weather can help keep everyone safe, productive and ready for the next day's work.