They are not going to melt in a PSK. I've carried one for at least 20 years in climates ranging from Arctic to African Desert. It's NOT like carrying a candle. If someone is worried about things sticking to one (never a problem in my experience), wrap it in a bit of cling wrap. But they do not melt at these low temps. <br><br>They are not a really important piece of kit - if you happen to have some lying around anyway, they are handy - a 1/2 - 1/3 stick is plenty or perhaps one of those extra-small ones. But I certainly would not go purchase a bag of glue sticks just to have one to toss in the ol' PSK or repair kit. I tossed one in my kit 20+ years ago because I had some left from a project. It has turned out to be useful a number of times (I'm sure I'm still on the original stick), but... I would have figured out something else to use or done without. Since we have them around the house for the intended purposes, all our repair kits have a stub tossed in intentionally, but I don't even think to recommend them to others who are assembling kits. Not really critical.<br><br>I have no idea if they burn or not. My guess is that they will be consumed in a fire but will not sustain combustion on their own - but that's just a guess. I recall using a disposable butane lighter to "melt" the glue on at least one occasion and using a stove-heated piece of metal (homemade ski wax iron) on at least two occasions, and beyond that, my memory is too vague. Like I said, it was handy to use, but not critical.<br><br>Last year I repaired a puncture in an ancient Thermo-rest mattress with the "proper" modern repair kit. Part of the stuff used for the repair is obviously a thermo-setting glue that is designed to become fluid in boiling water - the kit is designed to be usable "out on the trail". So it is apparent that at least some thermo-setting glues are designed to become fluid at ~ 190F - 200F or thereabouts (I'm assuming they made allowances for altitude driven drops in the BP of water). But even that is much higher than a PSK is going to get to in one's pocket. Like I said, I have had no problems in an equitorial desert, so...<br><br>My 2 cents worth. Hope that helps.<br><br>Scouter Tom