humid ... (too much)

In my first "come-back" week, I managed to run 70k, not too bad.

So this morning I get-up very early targeting a long run before work, to see if at least I can hold the distance of a marathon (regardless the pace).

BUT....

at 5.00am: Temperature 24C (around 80F), Humidity 95% ...

I was well prepared: took 2 bottles of water to hide in the bush for the out-and-back loop, wear NewBalance "Lightening Dry" socks, etc ... but at no avail :

after 1 hour, I was already struggling ... the shoes were full of sweat and at every step I could hear the "swoosh, swoosh" sound of overflown shoes...
The singlet was indeed simply beyond the capacity of saturation and also start to leak water along the legs...
I made it home in 2h15' of struggle @4'20" pace (7'00"/Mile), but the last miles were more a kind of crawl, spotting my high-rise building from afar like a oasis in the desert
(NOTE: living in a hi-rise can be sometimes psychologically very demanding for a runner. My home is in a building about 150m tall; even from distance, it looks very close, but maybe it is still 5/6km away !!).

resolution taken: during summer, I will avoid any run more than 1hr. If needed and if I would have the chance, I will double morning + evening to make 1h30' long run. Running longs in such heat does not make any sense (in a single run, I lost at least 2Kg of sweat, it is impossible to keep up rehydratation of such entity running on a daily basis..)