Ottawa Fire Services hazardous materials experts were called to an Orléans hotel Tuesday night after hotel staff reported a strong smell of chemicals in the pool area.
On arrival, staff said 10 children who had been in the pool were complaining of coughing and burning eyes.
Firefighters recognized the chemical odour after entering the four-storey hotel in the 3300 block of St. Joseph Boulevard.
Staff reported the pool had just reopened after undergoing renovations.
Hazmat staff checked the chlorine levels in the pool, which were determined to be normal.
But chlorine levels in the hot tub were tested and found to be high and the chlorinator to the hot tub was shut down until it could be checked for proper operation in the morning.
The pool area was closed for the remainder of the night.
Fire crews used high-pressure fans to ventilate the area and advised staff to leave the pool ventilation system on until the systems were checked.