Climate change could slash labor productivity in some countries by as much as 25 percent over the next 30 years, according to a report by Verisk Maplecroft on Wednesday.

The risk consultancy firm found that rising global temperatures and humidity could cause a dramatic increase in the number of days where it would be unsafe to do physical work.

“Incremental rises in global temperature and humidity due to climate change are likely to increase the number of working days exceeding safe levels of heat stress, which can cause absenteeism through dizziness, fatigue and nausea and even death in extreme cases,” Verisk Maplecroft said in its report.