Some Central Australian parents have expressed outrage after a group of children was given detention because they would not get into a swimming pool.

About 20 students from the Centralian Middle School in Alice Springs refused to swim because they felt it was too cold.

The water and air temperature was about 23 degrees Celsius at the time.

Mother Janet Brown says teachers need to respect a child's choice not to jump in cold water on a cold day.

"If the kids don't want to jump in it's because they're concerned for their personal health," she said.

"And when you put it as health and safety, I mean, goodness me, you'd have kids come down with colds and flus and everything else."

The school's acting principal Kaylee Kent says children do not have to enter the swimming pool when the temperature is below 20 degrees.

She says if parents do not want children to participate, they should send a note.