If you have ever experienced such a kind of a challenge from your authority’s inspector, you know what I am talking about.
One day an auditor entered my hangar and challenged the fact it was too cold. I got crazy, because I had no idea whether he was wrong or whether he was right!

It is true, the regulation says that temperatures must be maintained such that personnel can carry out required tasks without undue discomfort, but what exactly is such an undue discomfort? Is it perhaps enough asking the workers whether are they in any kind of “temperature discomfort”?

It seems it is not enough, as the auditor assumed the workers is perhaps lying for the sake of the Company’s benefit. Still according to the EASA regulation, the working environment must be such that the effectiveness of the personnel is not impaired.

Therefore I showed the auditor that there was no record or report, issued at working or managerial level, highlighting issues related to the supposed low temperature. Furthermore it is not written nowhere, how warm should an hangar be in order to prevent that workers effectiveness is impaired. Or maybe is it?

It turned out that there are some ICAO’s recommendations (published HERE by the FAA) where information on “Heating, Ventilation and Air Conditioning (HVAC)” are shared in order to provide with guidelines addressing such a matter (if you open the document, you could immediately go to page 71/147).

According to the ICAO, at 15.6ºC (60ºF), hand and finger dexterity begins to deteriorate and at 12.8ºC (55ºF), hand dexterity is reduced by 50%.

About the “high temperatures”, 32.2ºC (90ºF) is identified as the upper limit for performance, even though 26ºC (80ºC) is already highlighted to be the maximum acceptable upper limit.

If you are challenged with precise temperatures values, you now know where they are likely coming from, and knowledge is power. So, if the auditor is pushing you around by implementing whatever he wishes, you could open a discussion as the possible solutions are not necessarily the most expensive.

Cold stress can usually be effectively handled by providing windbreaks, local heat sources and, dry / windproof / layered clothing. Heat can be fought by using fans, air conditioning or personal cooling garments, as appropriate.

Have a look to the ICAO’s Human Factors Guidelines for Aircraft Maintenance Manual for further information, and keep in mind that the information hereby shared should be relevant for both production and maintenance.

I wish you not to find yourself in such a trouble.
Good luck!