A1 mini - garage or bedroom?

I got my son an A1 mini for Christmas. He's a bit worried about having it in his bedroom though because of the fumes. A quick google suggests PLA is the best option for this, but I don't know how safe it actually is.

The only other place we could put it is the garage, but it's unheated, and it does get cold here in the winter (England).

So... where is best for it. It's not really feasible to have the window open when it's printing (it would get too cold), but it is a big bedroom if that makes a difference?