President Donald Trump’s decision to withdraw from the Paris climate change agreement will endanger human health and make it hard to prevent even more damage from global warning, medical groups said Thursday.

Many studies clearly lay out the risks from climate change — including respiratory and heat-related illnesses, insect-borne infections, water-borne diseases, and threats to safe food and water.

A technician uses a blower to distribute mosquito bacteria larvicide granules to kill off mosquito larvae on July 21, 2015 in Bay Point, California. Justin Sullivan / Getty Images

“The elderly, the sick, and the poor are especially vulnerable,” the American College of Physicians said.

Related: White House Says Climate Change is Ruining Health

“Climate change needs to be aggressively addressed on a global level, and the Paris accord is central to this effort,” said ACP president Dr. Jack Ende.

“Without U.S. leadership, achieving the voluntary targets agreed to by the 195 countries that signed the accord will be far more difficult. Today’s decision therefore greatly increases the chances that the global effort to reduce carbon emissions will be insufficient to avert catastrophic consequences for human health.”

Other groups said climate change is already damaging people’s health.

“Unchecked climate change is a global health crisis that threatens to reverse decades of health gains worldwide, with serious consequences for our children and generations to come,” said American Lung Association CEO Harold Wimmer.

Related: Is Global Warming Making us Sick?

A 2015 study found that a rise in the average summer temperature of just under 2 degrees F led to a 1 percent higher death rate in New England, for instance. Heat can raise blood pressure and worsen cholesterol levels. Longer, hotter summers can aid the spread of mosquitoes that carry diseases such as malaria, dengue, Zika and yellow fever — and warmer winters may fail to kill off populations of the insects.

"Today’s decision therefore greatly increases the chances that the global effort to reduce carbon emissions will be insufficient to avert catastrophic consequences for human health.”

More extreme storms, including hurricanes, blizzards and tornadoes, can injure people as well.

“We know that climate change is happening and is already harming the health of Americans and other people around the world,” the newly formed Medical Society Consortium on Climate & Health said in a statement.

Related: CDC Climate Change Meeting is Back on, Without CDC

“The Paris Agreement is science-based and emphasizes clean energy and pollution reduction, which will improve health immediately and is a crucial tool with the potential to reduce the odds of more dramatic harms to health down the road,” added Dr. Mona Sarfaty, who heads the Virginia-based group, which includes the American Academy of Allergy, Asthma & Immunology; American Academy of Family Physicians; American Academy of Pediatrics and others.

But Health and Human Services Secretary Dr.Tom Price said the U.S. doesn't need the agreement.

“The Paris agreement is a bad deal for the American people. I applaud President Trump’s leadership and the actions he is taking," Price said in a statement.

"At the Department of Health and Human Services, it is our mission to promote and protect the health and well-being of the American people. This includes an already existing, robust commitment to advancing public health security both here at home and through partnerships with other nations.”

He did not elaborate.