OMAHA, Neb. -- The high temperatures and high humidity have formed a potentially deadly combination, according to the Nebraska Department of Health and Human Services.

The agency issued a heat alert Monday afternoon.

Temperatures above 90 degrees and humidity levels at 40 percent or higher can put people in the danger zone for heat-related illness, the agency said.

The body normally cools itself by sweating, said Dr. Joann Schaefer, DHHS Chief Medical Officer.

"When the humidity is high, sweat doesn't evaporate as quickly. That prevents the body from releasing heat, causing its temperature control system to overload"

The risk for illness is higher in infants and the elderly, and also those suffering from chronic illness, heart disease and obesity.

Symptoms of heat exhaustion include rapid heartbeat, cold, clammy skin, nausea, dizziness, weakness and fatigue.

Heatstroke is more serious.

Symptoms include a body temperature of 105 degrees or higher, hot dry skin, shallow breathing, rapid heartbeat, disorientation, delirium and coma.

The Salvation Army was helping with relief by giving away fans.

But the fans are almost gone.

The agency started with 250 in June.

Today, it has fewer that 40 left.

Some people, like Arletha Sims, are grabbing the fans because they can’t afford their air conditioning bill.

“A lot of things that help you are your ceiling fans and this fan. But to turn on that air right now, it’s kind of high right now. It’s high,” Sims said.

The Salvation Army's community cooling stations are open from 8 a.m. to 5 p.m. and each day that temperatures climb above 90 degrees.

The north Omaha location is at 2424 Pratt St. The south Omaha location is at 4032 Harrison St.