A health warning has been issued to tradespeople and outdoor workers across the UK, highlighting June 20 as one of the most dangerous dates for heat-related illnesses this summer. The Met Office has confirmed a higher-than-usual risk of heatwaves, with above-average temperatures twice as likely compared to historical norms.
Met Office Forecast
Met Office meteorologist Alex Burkill stated: "There are signs that we could see another heatwave by the end of the week and into the weekend. We could get temperatures, particularly across central-eastern parts, of 27C or 28C, so we could be looking at getting to heatwave threshold." He added that high pressure building across the UK is bringing warmer air, though uncertainty remains about exact temperatures.
No Legal Maximum Temperature
Unlike other European nations, the UK has no legal maximum working temperature, leaving outdoor workers without enforceable rights to stop work in extreme heat. Research from Protectivity, a tradesman insurance provider, analyzed weather data to identify the highest-risk locations and dates.
Top 10 UK Cities with Most Heat Days
- St Albans - 47 days over 27°C
- City of London - 45 days
- Oxford - 37 days
- Cambridge - 37 days
- Chelmsford - 34 days
- Birmingham - 33 days
- Gloucester - 32 days
- Worcester - 32 days
- Winchester - 31 days
- Peterborough - 29 days
Top 10 Hottest Dates for Outdoor Workers
- 12th August - 61 days over 27°C in last 3 years
- 20th June - 43 days
- 13th June - 42 days
- 11th July - 41 days
- 30th June - 37 days
- 11th August - 36 days
- 21st June - 35 days
- 12th July - 34 days
- 13th August - 33 days
- 25th June - 31 days
August 12 is the single hottest working day, but five of the top ten dates fall in June, including June 20. Chris Trotman, Underwriting Manager at Protectivity, noted: "The risk isn't concentrated in one place or one month... Five of the ten most dangerous dates fall in June, yet June is often when sites run at full capacity without heat protocols."
Safety Tips for Tradespeople
James Crame, Health and Safety Advisor at Start Safety, offers five tips for staying safe:
1. Conduct a Site Heat Risk Assessment
Document exposure factors like direct sun, PPE burden, access to shade and water, worker health, and acclimatisation status. Update at the start of each summer.
2. Implement an Acclimatisation Schedule
Gradually increase exposure over 5-7 days for new or returning workers to reduce heat fatality risk.
3. Reschedule Strenuous Tasks
Avoid peak heat hours (11am-3pm) by moving heavy work to early morning or late afternoon.
4. Establish a Work-Rest-Hydrate Regime
Drink small amounts of water every 15-20 minutes and rest in shaded areas away from radiated heat.
5. Review PPE for Heat
Use breathable, lightweight alternatives like vented hard hats and moisture-wicking layers. Remove PPE during breaks when safe.
