While that is true, the OPs concern was the short time period between changes in temperature. Not the case with Everest, as you are walking up VERY slowly. Next time, PLEASE, pay more attention to the issue at hand!
Well if we are splitting hairs, you don't walk up Everest you climb..
I think the proper term would be you ascend Everest. This allows for the process to include all modes of making progress including walking (progress utilising the lower limbs) and climbing (progress utilising arms and legs - even crawling is covered).