Grand Junction, CO – Two separate incidents involving carbon monoxide gas left two dead over the weekend, another two hospitalized and Utah Poison Control officials trying to spread awareness.

Steven Dowdy, 28, and Darian Thomlinson, 10, both of Grand Junction, Colo., were found dead in a tent at Ant Flats Road in southeast Cache County Sunday morning. Investigators believe the incident was caused by a heater in the tent that was attached to a 5-pound propane tank, said Cache County Sheriff’s Lt. Matt Bilodeau.

“We’re assuming that was the cause,” Bilodeau said. “But the official cause of death will have to be determined by the medical examiner’s office.”

Sunday afternoon, two others were hospitalized after being poisoned by carbon monoxide. Henry Horne, 69, of Redmond, Sevier County, was fishing

with his 15-year-old grandson on Fish Lake when it began to rain, said Sevier County sheriff’s deputy Nathan Curtis. He said they tried to pull a

cover over their boat, which trapped engine emissions at the same time.

Curtis said police didn’t know about the severity of the situation, only that Horne collapsed on the dock and was taken to the hospital with his

grandson.

Marty Malheiro, coordinator of outreach at the Utah Poison Control Center, said when people think of carbon monoxide, they don’t often think of scenarios outside their homes.

“People think, ‘yeah, generators in a house are bad,’ but anything that encloses the air can cause a rapid build-up of carbon monoxide fumes,”

Malheiro said.

Any time there is a small, gas-powered engine running in any kind of space, even those that are only partially enclosed, there is a risk, she said. Carbon monoxide is especially dangerous, because it’s often difficult to detect.

“It doesn’t have a smell,” she said. “People just tend to get tired and they don’t realize the effects and then it only takes minutes.”

Even though the symptoms of carbon monoxide poisoning can mimic other, more common illnesses, Malheiro said it is important to know them for the sake of awareness.

“They’re nauseous, dizzy, sleepy, malaise . it can mimic alcohol consumption, it could feel like the flu, but people need to recognize that

it can act like these other things,” she said.

Ultimately, Malheiro said, the key to preventing carbon monoxide poisoning “is really keeping those gas-powered things away from enclosed human

activity.”