New York CNN  —  This was supposed to be the year that air conditioning came to UPS delivery vans. It hasn’t worked out that way. Despite a promise in the contract reached with the Teamsters union last year, UPS has not yet purchased any new vans with AC, even as temperatures soar across the country and the dangers of extreme heat put workers in harms way in and out of doors. Almost none of the nearly 100,000 brown package vans have AC. Temperatures inside the trucks, both the cab and especially the cargo space where drivers need to go to fetch and drop off packages, can regularly get well over 120 degrees, according to the Teamsters union, which represents more than 300,000 UPS employees. The union’s demand for relief from the heat for its nearly 100,000 members working as delivery drivers was a major sticking point in contract negotiations last year between the union and the package delivery giant. It was far more than an issue of comfort; it was a worker safety issue, according to the union. Drivers have been known to suffer heatstroke, with some coming close to death, while on the job in the vans. And as part of the contract reached in late July of last year, UPS agreed that all vans purchased after January 1 would include air conditioning. UPS also agreed to retrofit existing vans with fans in the cab, heat shields under the cargo area and what are known as “scoop air intakes” in the cargo area. The fans have been installed in all the vans, UPS said. About two thirds have been retrofitted with the heat shields and air scoops, reducing the temperature in the rear cargo by about 17 degrees on average, according to the company. But there have been no vans purchased this year, so no additional AC vans are on the roads. The company said van purchase decisions are based on package volume and the need to replace existing fleet, and there has been no need to make purchases so far. The Teamsters are not pleased by the lack of progress on the AC. “We are midway into the summer, and frankly UPS is not moving fast enough,” said the union in a statement to CNN. “We are aware that UPS has installed all contractually required second fans, and UPS is ahead of schedule in the installation of heat shields and air induction scoops for package compartment ventilation. But it’s not enough.” There are a small number of vans – in the hundreds – that have AC. Those are electric vans, or specialized vans for rural area that can go on gravel roads, UPS said. But they make up only a small fraction of the 94,000 UPS package vans on American roads. The number of vans with AC was bound to grow slowly. Some vans can last for more than 15 years. Retrofitting the existing fleet was going to bring more immediate relief. UPS told CNN it is very concerned with workers’ safety and that AC was never going to be key to its heat mitigation efforts. In addition to the heat shield and air scoops, it has installed an additional 1,500 ice machines and 1,700 water fountains in its facilities. It said it also provided specialized cooling gear for UPS drivers and inside staff to wear, as well as water jugs for drivers. And for inside workers it has installed additional fans in its buildings and will install more. But AC is still a rarity in the UPS vans on the road.