DETROIT — Numb tongues, stomach aches, "seeing stars." It wasn't what two western Michigan women had in mind at the end of their Hawaii vacation.

Elizabeth Gass of Middleville and Deborah DeJonge of Ada said they were sickened when exterminators sprayed their Maui hotel room with pesticide after reporting a dead cockroach to management.

A federal appeals court said their lawsuit alleging negligence should go to trial, overturning a judge in Grand Rapids who had ruled in favor of Marriott Hotel Services and Ecolab.

"A jury reasonably could find that defendants were negligent in inundating an occupied hotel room with pesticide spray in the absence of any warnings to the occupants," the court said in a 2-1 ruling today.

A lawyer for Marriott and Ecolab declined to comment. A message seeking comment was left with an attorney for the women.

The incident occurred at the Wailea Beach Marriott Resort in September 2004.

DeJonge said they were at the beach when she returned to the hotel room and discovered exterminators and a "horrid" odor. They were preparing to depart that day, and their suitcases were open.

A short time later, after DeJonge and Gass felt ill, the hotel arranged transportation to an urgent-care center.

Back in Michigan, six weeks after the trip, DeJonge, 51, told her doctor about drowsiness, a swollen tongue and pain in her joints. Gass, 56, complained of chills, blurred vision, muscle spasms and a black tongue.

An Ecolab exterminator has testified that a co-worker applied only two quick squirts from an aerosol can.

Experts for Marriott and Ecolab have said the pesticide could not have caused the symptoms. A psychiatrist said the women's health problems were the result of stress.

In May 2007, U.S. District Judge Robert Holmes Bell ruled in favor of Marriott and Ecolab, saying there was not a direct connection between the pesticide and the symptoms.

The new ruling means the case will return to Bell's court for trial or settlement. Gass and DeJonge are seeking more than $50,000.

In his dissent, 6th Circuit Chief Judge Danny Boggs questioned whether a jury would be able to determine the cause of the "mystery illness."

"To be sure, an ordinary lay person probably begins with an assumption that black tongue is evidence of something gone wrong, but the question here is what that something is and whether it is chargeable to the defendants' actions," Boggs said.