That sounds awful. Fair play to you for still getting to work despite those conditions.
When I worked in a very hot office I researched cooling garments. There were vests, hats, scarves etc. It's a long time ago because I just changed job, couldn't take the long hours and roasting office anymore, but maybe google 'cooling garments' and see what pops up.
RR-MS dx 1998 and Coeliac dx 2003
Copaxone, Cymbalta. EPO, Fish Oils, Vitamin D3 2000 IU daily, Cal/Mag/Zinc, Multivitamin/mineral, Co-Enzyme Q10, Probiotics, Milk Thistle.