BOHS Meeting on the Thermal Environment

Working in extreme heat

We had a good turnout at the meeting today in Ellesmere Port 28 people turned up to listen to four speakers who covered a number of aspects of managing the thermal environment.

Doug Hiebert talked about how BNFL dealt with a problem at their Selafield site. Maintenance work has sometimes to be carried out in relatively high temperatures and high relative humidity and the risk is increased by the need to wear very comprehensive protective clothing to protect workers from the radiological hazards. One problem they faced when assessing the risk is that it wasn’t possible to use the usual equipment to carry out environmental measurements due to the potential for it to become contaminated.

After assessing the problem a number of measures were implemented including

• classifying the area as a “confined space” and introducing restrictions on acess based on factors that could affect an individual’s susceptibility to heat strain
• trying to schedule maintenance work during plant shutdowns
• introducing quite stringent and conservative time restrictions for work in the area
• providing cooling vests

Andrew Moore from the HSE was the second speaker. He provided a regulatory perspective but also gave some good advice on how to manage the health risks associated with work in hot environments. He stressed the importance of obtaining competent advice and effective management, ensuring that all the relevant stakeholders are involved. He illustrated his presentation with a case study where workers at a leisure pool were working in relatively high temperatures and high humidities. Although treated as a thermal comfort problem, the temperatures involved meant that the workers could be considered to be experiencing thermal stress.

I was the third speaker. Copies of my slides with notes can be viewed on Slideshare and a previous post.

The final speaker was Len Morris of the HSE who announced the formation of a BOHS Topic group on the thermal environment. Anyone interested in getting involved should contact BOHS HQ.

There are a number of good on-line information sources for anyone who’d like to find out more about managing the risks to health presented by the thermal environment, including the following

• the HSE thermal environment website
• the BOHS Technical Guide on the thermal environment andaddendum
• HSE’s guidance on heat stress

Visual Notetaking

I stumbled across this presentation on Slideshare the other day

I think it’s a really example of the modern approach to presentation design as advocated by Garr Reynolds and Nancy Duarte. It’s well designed and very visual. No not boring lists of bullet points here. The content is good and interesting too.

To understand the message fully you’d need to listen to the presenter – and that’s what presentations are about – the slides should support the presentation. With Slideshare that’s not possible (unless the originator records a soundtrack to go with it) so the full message doesn’t come across. However, the creator, Eva-Lotta Lamm, has made the notes that go along with the presentation available on her blog “Do Not Forget”

I like the idea of using sketchnotes and have tried to use them when I’ve attended conferences and meetings over the last 12 months – but I’ve not got the hang of them yet. I’m not a natural sketcher and I still find myself writing out linear lists. But I’m going to keep trying!

Thermal Comfort

The thermal environment is one of the traditional topic areas studied by occupational hygienists. There are two issues:

• thermal stress and strain
• thermal comfort

Excessive thermal stress means that the body has to work hard to avoid he core temperature moving outside narrow limits (37 + 2 C). If that happens we’re in a serious situation that leads to serious health effects and may be fatal. Our efforts to prevent this happening can also lead to adverse effects. This is most likely to occur in extreme environments or, sometimes, in more moderate environments where particularly heavy work is being performed or clothing is worn which prevent metabolic heat escaping.

Thermal comfort is most likely to be an issue in workplaces such as offices, but complaints or concerns can sometimes occur in manufacturing environments and other types of workplace. In this case the body is not experiencing a level of stress that it can’t cope with. There isn’t a physiological problem and ill health will not occur due to excessive thermal strain. But that encompasses a wide range of conditions. Will all of them be “comfortable”? Experience clearly shows that the answer to that is “no” !

Most occupational hygienists don’t work in industries work in high or low temperatures and so usually don’t have to deal with problems due to workers experiencing excessive heat or cold stress. However most of us, at some time or other, will be faced with a situation where workers are complaining that an environment is uncomfortable.

The BOHS is holding a Regional Meeting at Ellesmere Port tomorrow on the thermal environment. I’ll be giving a presentation on how to evaluate thermal comfort. These are the slides I’ll be using.

Thermal comfort for bohs version for slideshare notes

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