Dress code!

Clarifications

I would think you would be more apt to convince them of installing an air conditioning unit instead, not just for employee comfort, but for the preservation of electronic equipment.

Back in the 1980s and 1990s, yes, it was suit and tie.

But other than some Banks and law firms, business casual is the norm in most of the Fortune 500 US businesses at this time.

For example, here in Atlanta, we have headquarters for UPS, HomeDepot, and Coca-Cola....all business casual, except for possibly the very top executives...and even that can vary, depending on what meetings or activities are planned.

Someone will eventually require a hospital visit. Maybe that will enlighten the boss.
http://www.medicinenet.com/heat_stroke/article.htm

http://www.mayoclinic.com/health/first-aid-heatstroke/FA00019

http://www.bt.cdc.gov/disasters/extremeheat/faq.asp

Look up other info if you like. Search hyperthermia or heat stroke.

However, be aware that it is not a 'cut & dry' issue. Although most agree that relaxing the dress code a bit can have a positive effect on morale and productivity, your company managers may believe that projecting a professional appearance to your clients carries more weight.

Perhaps they should consider the cost associated with running air conditioners higher to compensate for the added discomfort and physical threat caused by wearing a suit and tie in 100+ degrees. (see the last article)

http://www.kon.org/urc/maloney.html

http://www.highbeam.com/doc/1G1-148710059.html

http://www.incoming.com/WebModules/QueueTips/Question.aspx?ID=281

http://www.deanstalk.net/deanstalk/2006/07/dess_codes.html

http://www.nationalseminarstraining.com/Articles/Category/Office_Politics/DRESSINGUP/index.html

http://www.busreslab.com/policies/goodpol2.htm

http://www.bco.org.uk/uploaded/24_Degrees_Full_Report_FEB_8.pdf

Besides the sharp dressed and clean cut service techs who provide onsite services, a tie presents a serious safety hazard when working around some equipment. I can't count the number of ties destroyed by myself and others working on high speed line printers and at least one occasion of a near choking event. Managers could care less about how hot it is outside when the customer's perception is concerned. Coveralls are provided for obvious dirty work but the tie must be present..Seems redundant and until hypothermia sets in there will be no suspension of said dress code. Clip on ties provide the safety protection but a bottoned collar provides no thermal relief and the coveralls just increase the hazards during 90 degree plus environments.