LENEXA (AP) – A northeastern Kansas woman is vowing not to spend another night in her home without a carbon monoxide detector after she and her family were sickened by the odorless gas.

Terrilynn Miller, of Lenexa, says she and her husband woke up around 4 a.m. Wednesday with nausea and headaches. They called the gas company, which urged them and their 12-year-old son to leave the house immediately. They called 911 when the mother and son became ill.

KCTV-TV 5 reports that crews traced the carbon monoxide to a leaky basement furnace. Lenexa Fire Battalion Chief Eric Ramsey says the gas had reached about 500 parts per million in the basement – a level he says could have resulted in tragedy.

The Millers were treated at a hospital and released.