Jim Gillies has reminded me why I moved to PVA: I, too, found that
prolonged use caused a dull headache.  As an apprenticed organ builder
the hot glue pot was a feature on every work bench and I can remember
some of the bench hands complaining of headache whilst using the stuff.
And later, when I worked for Dug Berryman of The West Cornwall Museum
of Mechanical Music, he also said he couldn't stand hot glue, the smell
got right up his nose, so he used white PVA as well.

Using a fan to blow away the fumes is a good idea, but as I am no
longer involved with hands-on restoration any longer I probably will
never get the opportunity to try this out.

Cheers
Paul Camps