Dryer Vents? I just installed a Aluminum dryer vent. Is it ok if when...

I just installed a Aluminum dryer vent. Is it ok if when the dryer runs the outside of the aluminum duct gets hot? I don't want to start a fire. Any direction would be great!
Answers:    it should be, you're ducting hot air through it. By the time it eaches the wall and the outlet, it should have cooled stale considerably. Good to be concerned though.
yes that's normal,your venting the dryer nouns to the outside,and the duck will get very melt,hope that helps.