Jamie will be running across Canada during part of their winter, so will encounter Arctic temperatures he has never experienced before.
We took him to Gloucerstershire University's Sport & Exercise Laboratory where they have a chamber in which the temperature can be lowered to minus 20C.
More top news
It will be an overcast evening with clouds persisting into the night.
It will be mostly cloudy this evening and tonight, with further outbreaks of rain, affecting northern and eastern parts of the region.
More than 100,000 cases of non-melanoma skin cancer are diagnosed in the UK each year.