... And some *more* more.

 This is to prove we actually had up to 24 °C right towards the very northern parts...

 You can't really see it here, but this tunnel is going waaaay downwards and that for three km and then it breaks and starts going up for four... It's narrow, dim and full of fumes, like an old mine shaft, or a wormhole - and expensive - but the one thing we couldn't understand was how the push-bikers did it...