WA people are being reminded to be careful around fresh water that may infect them with amoebic meningitis, which thrives in water between 28C and 40C.

As temperatures rise, getting fresh water up your nose could lead to a potentially fatal infection, the West Australian Department of Health warns.

People are reminded to be careful to prevent getting amoebic meningitis, a rare but fatal infection caused by the Naegleria fowleri amoeba, which lives in fresh water and damp soil.

When water with the amoebae enters the nose, the amoebae travel to the brain, causing inflammation and destruction of brain tissue.

But infection cannot occur by drinking water.

Environmental health water unit manager Richard Theobald said it was important for people to be aware of the risk with recreational water activities.

"In addition to pools and spas, children often cool down in water from garden hoses or sprinklers, wading pools, and on regional properties, dam and lakes," he said.

"As amoebae thrive in water temperatures between 28C and 40C, it should be assumed that any warm, fresh water potentially contains the Naegleria fowleri amoeba."

There have not been any cases of amoebic meningitis in WA since the 1980s, but Mr Theobald said it was dangerous to be complacent.

Pool and spa owners are advised to closely monitor and check chlorine levels are within a safe range.

Risk of infection can be reduced by not allowing water to go up your nose when showering or washing your face, running taps to flush out the pipes before using the water, and letting hose water go cold before children play in it.