Sarah Dalton, executive director of the Association of Salaried Medical Specialists, said the so-called "winter surge" was now "the new normal" in many hospitals.
"It's not unusual for our medical wards to be over 100 percent occupancy even outside the winter surge.
"So if we get flu at the same time as Covid-19, that seems like too many things."
Health workers had borne the brunt of the Covid-19 outbreak in China and their experience showed clear protocols and protective equipment were needed now, before the virus arrived, she said.
