In the UK there is no maximum. You have to assess "the thermal environment" and the tasks / clothing they are using, and this requires specialist equipment to measure.

Hi Butros
I carried out a heat stress study a few years ago in the UAE[ in August!].
I also note from checking on the net today that there a still no regulations in place to tackle this serious problem.
The end result of the work I did was to get the company [Oil: Abu Dhabi] to upgrade it's approach to the problem and introduce a heat stress policy based on the recommendations.
Crucial issues which you will find discussed on the net are the WetBulb Globe Temperature (WBGT) which is a measure of the heat stress in direct sunlight, which takes into account: temperature, humidity, wind speed, sun angle and cloud cover (solar radiation) and process heat into an easy number, not easy to manage of course.
Together with this you need to account for the strenuous nature of the work and balance the two.
Typically the WBGT levels deemed acceptable are surprisingly low -which accounts for the shying away of Businesses and Govt from the regulatory track perhaps.
So strictly speaking there are loads of guidelines to choose from; your problem will be gaining commitment to one.
I don't think my work moved very quickly on in practice and I know from speaking to the medics that many of the labourers from places distant were the main ones at risk not the oil co employees [think Qatar and football]
Goodluck with it
Regards
Mike

Thanks Mike & Chris. I have arranged a meeting with the other Departmental Managers to debate on an internal agreed limit based on several factors. Common sense, backed up with some health data and a bit of moral grounds really. Mike thank you for the WBGT info. It must have been a seriously time consuming exercise. I am surprised that with the amount of outdoor work across the globe in extreme climates there is no clearer defined rule or parameters to meet. I guess due to the amount of contributing factors PPE , exposure, type of work, timescales ect. it has to be left open to what is practical at the time. Works well as long as you have Management who care.
Thanks again.

In my limited experience of middle east (Qatar/UAE/Oman) i was informed that there is a notional temperature of 50 deg when work would be stopped at government level and this was common across the region. I dont think any thermometer actually read that high and 49.9 was the highest i saw officially. Call me cynical. We instituted a number of measures for our workers including cooling rooms, frequent breaks, additional hydration reorganisation to night work etc etc but some of the local labour bosses were not keen on our soft approach!

The 1992 Workplace regulations only refer to indoor temperatures and states.. "if a reasonably comfortable temperature cannot be achieved throughout a workroom, local heating or cooling (as appropriate) should be provided. In extremely hot weather, fans and increased ventilation may be used instead of local cooling". Reg 7(i) only refers to "reasonable temperatures", so it's what you deem reasonable I expect. Does the UAE not have their own Regs?

Butros,

Having worked in the Middle East and undertaken Heat Stress Presentation on Behalf of the Dubai Municipality. If a remember correctly, once the temperature reached 50 degrees Celsius (122 degrees Fahrenheit), it was advisable to stop work. However, officially it never reached that temperature, unofficially it exceeds that by far in the desert.

Dubai Municipality made it compulsory for companies to give labourers who work in open areas (such as construction sites) a two and a half hour break between the hours of 12.30pm and 3.00pm. These restrictions come in effective from 15 June to 15 September. Labourers working in open spaces must not work between these hours and employers are required to provide a shaded area in which labourers can rest during this period.

The times have been changed by companies and start at 1100 – 1130hrs based on their Heat Stress Assessment – which is done based on Environment Factors, personnel and job. Once this is done then the control measures are put in place. Of course all people working for the company should be put through training as well on Heat Stress and Symptoms etc.
There is a chart called the Heat Index (HI), the index combines air temperature and relative humidity in an attempt to determine the human-perceived equivalent temperature – or how hot it feels to the person. The results are also known as the “felt air temperature” or “apparent temperature”
When a temperature is 32°C with humidity of 55%, the HI or apparent heat a person feels can be about 41°C. Do not just refer to the site thermometer reading, you have to know the humidity level.

During the Heat Stress Assessment, I would personally look at the clothing, food intake as the workers in the Middle East usually have on clothing that is not the best for working in hot environment and the food intake (daily diet) does not give them the supply of electrolytes to replenish the body, as it will be a mainly carbohydrate based food, which in-turn will take up more water from the body to digest the food in the intestine.

In addition, there is a hydration supplement (organic) that is given to the workforce to add to the bottle water companies supply. It is called eletewater - http://eletewater.co.uk/
Heat Stress is a serious problem that is ignored by many in my experience. It is a key factor that has to be taken seriously, otherwise it will occur without you even knowing and you may find yourself working on a lifeless individual or investigating “why” it occurred. Either way it is not a pretty experience, take it from some who knows…the individual suffered from heat stress in April

Butros,

No problem here if I can assist, yes the workforce can be stubborn to say the least. The Electrolyte that they refer to maybe the powder formula, the eletewater is an organic version that you can add to water and there will not be much taste to it.

Good luck