Hibernation
These toads live in an extreme environment. Temperatures range from 82 degrees in mid summer to 30 degrees below zero (-30) in the darkest months of winter. Ice and snow can lock the toads in their hibernation burrows for eight to nine months at a time.
Just imagine, September through April, close to three-fourths of their year is spent in hibernation. Some cold climate amphibians have an antifreeze-like substance in their blood that makes hibernation in cold climates possible. It is unknown if boreal toads contain this substance.