The International Committee of the Red Cross has released a manual on how to deal with dead bodies, rejecting the idea that corpses are a huge health hazard.
It came as the death toll in the Philippines from Typhoon Haiyan passed 4,000.
The storm crashed into the central Philippines on 8 November, destroying almost everything in its path.
Bodies are still being pulled from the debris. Many victims have been buried in mass graves.
The Red Cross said that, contrary to popular belief, there is no public health justification for rapid mass burials.
"The bodies of those who die in a natural disaster do not cause epidemics, and they are a negligible health hazard," it said in a release.
It said it was unlikely the typhoon victims were carrying epidemic-causing diseases such as cholera, typhoid or malaria and that they likely died from drowning, injury or fire.
"There is only a small risk of developing diarrhoea by drinking water contaminated by the corpses - a risk smaller than that caused by the living - and that risk can be eliminated by routinely disinfecting and/or boiling water to prevent water-borne disease."
The guide said the rumours about contamination put political pressure on authorities to resort to rapid mass burials and spraying disinfectants.
"The consequences of mismanagement of the dead include mental distress and legal problems for relatives of the victims," it said.
But it added that rapid retrieval of bodies was a priority because it aided identification and reduced the psychological impact on survivors.
In a section on advice for journalists covering disasters, it said they should challenge any call for mass burials or incineration.
"Please do not jump on the bandwagon of alarmists spreading incorrect information," it said. "Be professional."