Sanding, staining and varnishing wood, outside
Mario, I've been stripping paint off old doors, sanding, staining, and applying poly outside.  It's more convenient in dealing with the mess and smells and more enjoyable than being cooped-up indoors all the time.  

However, be aware that applying poly outdoors is best done inside a screened-off enclosure as every insect or airborne speck of dust, dirt, or pollen will choose that moment to land on your work otherwise.  A single errant leaf or breeze-blown blade of grass can wreck havoc on a poly' job that's just become tacky to the touch.  Also note: too much of a breeze can dry-out stain (before one has a chance to wipe the excess) and poly too quickly for the job to be done well.