Mill wells are present at lower altitudes. These are the melt water channels and chutes where water runs into. Falling into a mill well can be extremely hazardous as the tendency is to become trapped under the glacier, making rescue highly difficult, if not impossible.
Seracs are large ice towers that can easily become falling blocks of ice as the sun warms them. They are always potentially hazardous and should be passed quickly, without lingering.
Boulders can become loose from anywhere around or on the glacier at any time. Climbing near lateral moraines is most risky because rock falls can occur as a result of warming; try to schedule climbing time near lateral moraines early or late in the day.
Glacial streams are full of silt and can behave like quicksand; take great care in crossing them.