Climate change is already wreaking havoc on public health around the globe and the impacts will continue to mount as the crisis fuels prolonged heatwaves, extreme weather events and infectious disease, according to a new report published Wednesday by top medical journal The Lancet.

The Lancet Countdown is a comprehensive annual assessment tracking links between climate change and human health. This years report outlines how two potential emissions pathways business-as-usual and meeting the goals of the landmark 2015 Paris climate agreement will impact human well-being. It finds that without immediate action to rein in greenhouse gas emissions, climate change will come to define the health of people at every stage of their lives and challenge already overwhelmed health systems.

Renee Salas, an emergency medicine doctor at Massachusetts General Hospital and lead author of an accompanying brief focused on U.S. impacts, told reporters this week that the crisis is one of the most pressing health emergencies.

With every degree of warming, a child born today faces a future where their health and well-being will be increasingly impacted by the realities and dangers of a warmer world, she said. Climate change and the air pollution from fossil fuels that are driving it threatens the childs health starting in the mothers womb and only accumulates from there.

The last four years were the four hottest on record , with 2018 coming in fourth behind 2016, 2015 and 2017. Globally, an additional 220 million people age 65 or older were exposed to heatwaves last year, topping the previous record of 209 million in 2015, according to findings. Rising temperatures are having major implications on the global labor force, resulting in an estimated 133.6 billion lost work hours in 2018 up from 88.5 billion in 2000.

Global warming has caused a spike in infectious disease, including the mosquito-borne tropical virus dengue fever. According to the report, 9 of the 10 most suitable years for the transmission of dengue have occurred since 2000. Additionally, the number of days suitable for Vibrio, a pathogen that can cause diarrheal disease and infection, have doubled since the early 1980s. Children are among those most susceptible to such diseases.