The dead bodies were effectively freeze
dried by being buried under rock and with steady cold breezes
almost continuously blowing. The overhang protected them from
rain and snow, helping to keep them dry, being in the shade
would mean that they would not thaw out in the warmth of the sun
and so start to rot before they were freeze dried.
There were two graves, in the
first were three women stacked one above the other, then a boy
above the women and finally a baby, below:

The mummy of the baby found at Qilakitsoq,
a 6 month old boy, for 15th Century Greenland
Air temp: +7º C Latitude: 70º 51' N Longitude: 53º 53' W
These are pictures
from a cruise to the High Arctic in August 2010, from Resolute
Bay Canada to Kangerlussuaq in Greenland.
Pictures copyright Paul Ward.
Pentax digital equipment.