When it's really hot...

...it's good to find a place in Poznań, which makes you feel better:

a place to sit and relax (the Park near Stary Browar)

drink something refreshing (at the top of Galeria MM)

go into the green (tram stops in Poznań advertising National Forests):

by the way I really like the tramstops in Poznań - they are so well taken care of!

and last but not least... check the water in fountains!