Hot, sticky summer weather is uncomfortable and dangerous. It can cause heat stroke. And if people have underlying health conditions, it can even trigger crises like heart attacks.

“When we look at major heat waves, you see that lots of people died not just from heat stroke, but from cardio-respiratory diseases. And it’s because of the strain the heat puts on our various organ systems,” says Kristie Ebi of the department of global health at the University of Washington.

She says senior citizens are especially vulnerable because they often have chronic health problems such as diabetes or heart disease. And they may not notice the warning signs of heat-related illness.

“Many older adults don’t necessarily feel well on a good day,” Ebi says.

So she says it’s important to check on neighbors and family members when it’s hot.

“Do you have your windows and doors open? If you’ve got air conditioning, do you have your air conditioning on? Are you drinking sufficient fluids?” Ebi says.

Cities can help by issuing early warnings about heat waves and opening cooling centers.

As the climate warms, many parts of the country will see more extreme heat, so Ebi says it’s urgent that communities take action to keep everyone safe.

Reporting credit: ChavoBart Digital Media and Diana Madson