Hot weather could disrupt vital cancer screening for one million rural Australians, prompting calls for better public health education in country communities.

The national bowel cancer screening program delivers home tests to Australians aged over 50, but the kits are not sent out when regions experience average heat above 30.5C.

The hot zone policy prevents deterioration of samples, but also means people in some rural and remote areas have a shorter window in the cooler months to self-test.

A study by the Daffodil Centre, a cancer research organisation, for the first time calculated 1.02 million eligible Australians are affected by the policy, often in areas with higher levels of disadvantage and already low testing rates.

But targeted interventions like education campaigns ahead of cool weather and direct assistance from health workers could reduce mortality rates.

"The hope is that when there's planning around campaigns or government restructuring screening that they're not applying a one-size-fits-all approach," the study's lead Joachim Worthington told AAP.

"It's mostly just ensuring that whenever planning is made about the screening program ... rural areas aren't left behind."

Research has previously shown low testing rates in rural and remote areas, possibly because of stoicism, geographic barriers and poor access to healthcare.

"People can lose faith in the health system and the thing that drops off quickest is preventative health, or proactively doing things to prevent disease," Dr Worthington said.

The Daffodil Centre, a joint venture between between Cancer Council NSW and the University of Sydney, examined the effect of the hot zone policy after concerns national testing would be suspended during the height of COVID-19.

Estimates showed any three-month testing pause could increase mortality rates up to four times in hot regions, according to the study presented at the recent Rural and Remote Health Scientific Symposium.

Dr Worthington said the finding should inform the approach to bowel cancer testing after other disasters like floods and fires.

"That's likely going to decrease the chance that people are thinking about screening or that it's a priority for them," he said.

"This work emphasises that when things like that happen, we need to be looking out for these communities and making sure they get back into screening."