Today, OR-OSHA adopted temporary rules to protect workers from excessive heat - these rules are effective immediately. The rules apply to all industries and are triggered by a heat index of 80 degrees. Additional protections are triggered at 90 degrees. Employee training, as required by the temporary rules, must be completed by August 1.
Note that the rules aren’t specific to outdoor work, so workplaces with an outdoor component or lack of HVAC, such as open garage doors or drive-through windows, may find they are brought in under these temporary rules.
CDC/ OSHA/ NIOSH have a heat safety app that is a useful tool to discern heat index, which can be found at this link.
Please check the OR-OSHA website for tools in the upcoming days to help employers create training materials and acclimatization plans.