Imagine you live in Pedregal Grande, a poor neighborhood in Piura, Peru. Residents get running water for only 30 minutes each day. You store all the water you can in plastic tanks.

What loves tanks of standing water? Mosquitos do. They gather in your water tubs and breed.

Meanwhile, hot weather forces you outdoors. (Most people in Pedregal Grande don’t have air conditioning.) Mosquitos descend on you . . . because you are what mosquitos love to eat. And when they take a bite, they spread a disease called dengue (DEN-gee or DEN-gay) fever.

“You go out to get some air and the mosquitos arrive suddenly and attack you,” says Segundo Ramos. He’s a Peruvian driver. He got the disease several days ago.

“My neighbor has dengue. Over there they also have dengue,” says Mr. Ramos. He sits in his one-story house in the 97-degree weather. “There are three or four sick neighbors within 100 meters.”

Other cities in the country have a huge dengue problem right now too. More than 34,000 cases of dengue were recorded in Peru in the first eight weeks of this year. That’s twice as many as last year at the same time. Why so much illness? It’s partly because of unusually warm weather caused by El Niño. Mosquitos love heat.

Authorities declared an emergency. They set up areas in hospitals just for dengue patients.

Santiago Valdez is a specialist in tropical diseases. He says the way people store water is a big part of the problem. “People are forced to collect [water] and no matter how much one tries to have closed containers, there is always carelessness and the mosquitos take the opportunity to lay their eggs,” he says.

Pray for the people of Peru. Dengue can cause severe headaches, fevers, and muscle pains.

People in Honduras have a creative way to fight dengue. Their secret weapon? Mosquitos! Learn how they build a better bug bite.

Bless the Lord, O my soul, and forget not all His benefits, who forgives all your iniquity, who heals all your diseases. — Psalm 103:2-3