Hazards and control measures
Weather hazards at work: wind, rain, heat and cold
The weather hazards at work: wind at height and for lifts, rain and ice, lightning, heat stress, sun and cold. What the law says, why there is no maximum working temperature, and the controls HSE expects. With a worked example from a completed RAMS.
What are the main weather hazards at work?
The main weather hazards at work are wind on people at height, on lifts and on temporary structures, rain and ice making surfaces slippery, lightning, and heat, sun and cold acting on the body. The Work at Height Regulations 2005 allow work at height only when the weather does not put the people doing it at risk. There is no legal maximum working temperature, so heat and cold are managed through the risk assessment: check the forecast, plan the day around it and set the limits before work starts.
Last updated . Facts checked by the SiteSurvey team on 24 October 2026 against HSE: Temperature in the workplace, the law, HSE: Temperature in the workplace, outdoor working, HSE: Heat stress and HSE: Outdoor workers and sun exposure.
Where weather becomes a hazard
Weather turns ordinary work into dangerous work. Wind catches a roofing sheet as it is lifted onto a roof, pushes a load swinging on a crane hook, loads a stage roof or a banner like a sail and makes a mobile tower unstable. Rain and ice make scaffold boards, ladders, steel and stage decks slippery and turn site routes to mud. Lightning puts anyone on a roof, a truss, a crane or a MEWP at risk. Heat, sun and cold act directly on the body.
It shows up in every outdoor trade: roofers, scaffolders, steel erectors and crane crews, event riggers building stages and marquees, grounds and tree workers, and anyone doing maintenance on a flat roof. Temporary structures are the most exposed, because they are light, tall and often in open spaces, and because loose materials left at the end of a shift can be blown off overnight.
Who is harmed, and how
Wind and wet surfaces cause falls from height, dropped and blown materials, and lifts that go wrong, so the people harmed are the crew at height and anyone below or nearby, including the public. A collapsed temporary structure can harm a crowd.
Heat stress happens when the body's way of controlling its internal temperature starts to fail. HSE lists early signs such as an inability to concentrate, muscle cramps and fainting, then heat exhaustion and heat stroke, which can end in loss of consciousness. Heavy work, humidity and protective clothing all add to it. The sun does longer term harm: UV rays cause sunburn and skin ageing, and the most serious effect is an increased chance of skin cancer. People with fair or freckled skin that burns before it tans are most at risk. Cold slows hands and judgement, which matters most on a long overnight shift at height.
What the law expects
The Work at Height Regulations 2005 say work at height may be carried out only when the weather conditions do not jeopardise the health or safety of the people doing it. On an outdoor construction site, CDM 2015 requires the site to be arranged, so far as is reasonably practicable, to give protection from adverse weather. There is no maximum temperature for workplaces. The 16 C minimum, or 13 C for work involving rigorous physical effort, comes from the Approved Code of Practice and applies to indoor workplaces, so outdoor heat and cold are handled through the risk assessment.
Work through the controls in order. First avoid the exposure: check the forecast each morning, reschedule heavy or high work to cooler or calmer times, and set a wind limit for each lift and each structure, with work stopping above it. Then engineer it out: weight or remove loose sheets and materials at the end of the shift, and give shade or shelter to work and rest areas. Then manage it: rest breaks, cool drinking water in heat, hot drinks and a warm place in cold, a lightning procedure that brings everyone down from height, and workers trained to spot the early signs. Clothing, hats, sunscreen of at least SPF30 and cold weather gloves come last. In SiteSurvey, the RAMS template records the weather controls for the job and warns when only PPE is ticked, and the Suggested controls list follows the same order.
Suggested controls
Weather, heat and cold: control measures, most effective first
These are the 5 controls the SiteSurvey RAMS and risk assessment forms offer for this hazard as a tick list, grouped by their level in the hierarchy of controls. They are a starting point from HSE guidance, not an assessment of your job: tick what applies and say how it works on your site. If only personal protective equipment is ticked, the form says so. How suggested controls work and the hierarchy of controls explained.
Change the way the work is done: a permit, a check, training, supervision, timing.
- Forecast checked each morning and work replanned around it
- Work at height and lifting stopped above the wind limit for the job
- Loose materials weighted or taken down at the end of each shift
- Shade, water and breaks in heat; warm clothing and breaks in cold
- Lightning procedure agreed: stop and come down from height
Offered to: Construction and building work, Roofing, scaffolding and work at height, Events, exhibitions and staging, Grounds, landscaping and tree work.
Try it
Build the controls for weather, heat and cold
Tick the controls you would put in place, see which levels of the hierarchy they reach, and score the risk before and after. Or fill in the example from a completed RAMS to see how one crew did it.
Interactive
Try it: weather, heat and cold
Works the same way as the RAMS form. Nothing you tick is saved or sent anywhere.
Your controls, by level
- Eliminateno control at this level for this hazard
- Substituteno control at this level for this hazard
- Engineeringno control at this level for this hazard
- Adminnot ticked
- PPEno control at this level for this hazard
Nothing ticked yet.
3. Score the risk with these controls
What the law says
- Work at Height Regulations 2005, regulation 4(3)
- Work at height is carried out only when the weather conditions do not jeopardise the health or safety of the people doing it.
- Construction (Design and Management) Regulations 2015, regulation 34
- A reasonable temperature indoors on a construction site, and protection from adverse weather on an outdoor site so far as is reasonably practicable.
- Lifting Operations and Lifting Equipment Regulations 1998, regulation 8
- Every lifting operation properly planned by a competent person, appropriately supervised and carried out in a safe manner.
- Management of Health and Safety at Work Regulations 1999, regulation 3
- The suitable and sufficient risk assessment that covers the weather, heat and cold for the work, indoors or out.
Worked example
Weather, heat and cold in a completed RAMS
The hazard entry exactly as it was recorded in one of our completed example RAMS: the controls ticked from the list, how they apply on that job, and the score before and after the further action.
Events, exhibitions and staging
Durham Market Place Christmas lights switch-on: covered stage build
- Hazard
- Weather, heat and cold: Whole site, late November, open square
- What could happen, and to whom
- Wind loading the roof skin and the arrays, gusts catching the roof during the raise, rain and ice on the deck and the truss, lightning, and cold affecting the crew's hands and judgement through the overnight breakdown. The crew, the artists and the audience.
- Controls ticked
- Forecast checked each morning and work replanned around it
- Work at height and lifting stopped above the wind limit for the job
- Loose materials weighted or taken down at the end of each shift
- Shade, water and breaks in heat; warm clothing and breaks in cold
- Lightning procedure agreed: stop and come down from height
- How they apply on this job
- Limits are those in the supplier's wind management plan WMP-NL-114. Amber at 11 m/s mean: no work at height or lifting, side walls opened, banners down. Red at 15 m/s mean or gusts of 20 m/s: arrays and trusses landed and the roof lowered to its lowest position with the skin still on, nobody on the deck. K. Ashworth checks the Met Office forecast at 06:00 and 12:00 each day and reads the anemometer hourly; readings go on the sign-off sheet. Lightning within 10 km: everyone off the truss and the MEWP, hoists left locked, crew to the trucks until 30 minutes after the last thunder. Cold: warm, waterproof clothing, hot drinks in the production truck, and a rotation during the overnight breakdown so nobody is on the truss for more than 45 minutes at a time. The deck is swept and gritted if it ices.
- Risk with these controls (likelihood x severity)
- 3 x 4 = 12 (Medium)
- Further action
- Wind limits and the red and amber actions written on the whiteboard in the production truck and read out at the briefing. K. Ashworth has the authority to stop the show and lower the roof, agreed in writing with the council's events officer. Owner: K. Ashworth.
- Residual risk
- 2 x 4 = 8 (Medium)
A fictional job, filled in as a worked example. The form and the report are real.
It also appears in felt roof renewal on a school sports hall and independent scaffold on a seafront hotel. All eleven completed RAMS.
Weather, heat and cold: common questions
Is there a maximum temperature for working outside?
No. HSE says there is no maximum temperature for workplaces. Heat is still a hazard you must assess and control. That means rescheduling heavy work to cooler times of day, shade over work and rest areas, more frequent breaks and free access to cool drinking water.
Do the 16 C and 13 C minimums apply to outdoor work?
No. Those figures come from the Approved Code of Practice for the Workplace Regulations and are for indoor workplaces: normally at least 16 C, or 13 C where much of the work involves rigorous physical effort. Outdoors, cold is managed through the risk assessment. HSE suggests suitable protective clothing, mobile facilities for warming up with hot drinks, more frequent breaks and, where safe, delaying the work to a warmer time of year.
What wind speed should stop work at height or a lift?
The law does not set one figure. The limit comes from the equipment and the job: the crane, MEWP or tower manufacturer's limit, the lifting plan, or the supplier's wind management plan for a temporary structure. Write the limit into the RAMS, say how wind is measured and who calls the stop. In the worked example below, work at height and lifting stop at an amber limit and the stage roof is lowered at a red limit.
How do we protect workers from the sun?
Plan the hottest, sunniest work for cooler parts of the day and give shade where people work and rest. HSE advises outdoor workers to keep their top on, wear a hat with a brim or neck flap, use sunscreen of at least SPF30 on exposed skin and drink plenty of water. Workers should check their skin for moles or spots that change and see a doctor promptly if they find one.
Last updated . See every hazard in the library.
Write the RAMS with these controls already listed.
Pick the hazard, tick its controls, score it and brief the crew, on a phone or laptop. The report goes to the client as one PDF.