Anyone who¡¯s had to go to work on a hot summer day knows how exhausting it can be. Brain function slows, commuting is more uncomfortable and, for people who work outdoors, simply staying safe becomes a challenge. All of these factors combined add up to a heat-related hit on worker productivity, which stands to get more pronounced as climate change drives more intense heat waves.

¡°We used to think, ¡®Well people get hot and they sweat and they¡¯re fine.¡¯ But now we know that¡¯s not necessarily the case,¡± says Jill Rosenthal, director of public health at the Center for American Progress, which this month released a report on the threat extreme heat conditions pose to workers in the U.S.

Quantifying that threat can be difficult. Broadly speaking, it includes everything from weather-related commuter disruptions to diminished cognitive performance, poor sleep and added time off when kids are kept out of schools that lack air conditioning.