Negotiations between UPS and approximately 340,000 workers represented by the International Brotherhood of Teamsters have been ongoing for several weeks, in advance of a July 31 expiration of the current contract. A strike, which would be the nation’s largest ever and the first for UPS since workers walked out in 1997, would take a large chunk of the logistics sector offline and disrupt the national economy. The Teamsters have a number of demands, including two-tiered wage scales and the company’s overreliance on part-time and gig economy–style work. But one of their bigger issues was not related to pay, benefits, or job security. It was the heat.

UPS package delivery trucks, the famous brown ones that drive through neighborhoods, do not have air conditioning, a fact the company justifies by saying that the vehicles frequently start and stop, requiring workers to shut the engine and open the doors. Thermometer readings in the back of UPS trucks have reached 150 degrees Fahrenheit on occasion. Numerous drivers have suffered from heatstroke, dehydration, and other consequences, including several deaths. And another hot summer is approaching.

Alleviating the heat problem was a major focus for negotiators. And yesterday, they announced a breakthrough. The Teamsters and UPS announced a tentative agreement to add air-conditioning to the fleet. All new package delivery trucks will get equipped with AC, and use of those trucks will be prioritized in the hottest areas of the country. Existing package cars will get two fans installed, one within 30 days of ratification of the contract, and a second by next June.

New vehicles will also have "heat shields" installed in the cargo floor, which UPS estimates will minimize temperatures by up to 17 degrees. Those heat shields will be retrofitted onto existing package trucks. An induction system that flows fresh air from the front of the truck into the cargo area will also be installed on new trucks and retrofitted onto old ones. Overall, these changes will affect the majority of the 93,000-strong UPS fleet. The larger UPS tractor trailers already had air conditioning.

"Teamster members in these vehicles will get the relief and protection they’ve been fighting for," said General President Sean O’Brien in a statement. "We are here to protect more than 340,000 UPS Teamsters and get the best contract in the history of our union with this company. Today’s progress was a significant step towards a stronger new reality for so many workers and their families."

UPS is a big enough employer that its attention to extreme-heat dangers could spur action for other workers, like FedEx trucks or Amazon warehouses. The Occupational Safety and Health Administration published an advance notice of proposed rulemaking on extreme heat in workplaces in 2021, but it’s nowhere close to completion. The agency has not initiated an interim heat standard while the rule is finalized.

All of these advances are contingent on UPS signing a final contract. The two-tier system (known as 22.4 after the numbered provision in the 2018 UPS contract) continues to be a sticking point; 22.4 drivers work full-time shifts at lower than full-time wages, without the same control over schedules. The Teamsters also want to increase pay for part-timers who work in UPS distribution facilities and make as little as $15.50 an hour. And UPS has begun to use personal-delivery drivers who deliver in their own cars during peak seasons like the Christmas holidays; this non-union DoorDash-style workforce is looked upon unfavorably by Teamster members. A strike authorization vote has been called, and the results will be announced Friday.

Bargaining continues with about six weeks until the deadline. But earning better conditions for drivers after years of dangers is a big step forward.