TrackIR 5 temperature problems?

I just bought my fist TrackIR 5 (Love it this far!). But I am a bit worried because I noticed that it gets very hot. I first thought it was because I had just flown a 1h+ mission with it but after some further testing and reading it seems like it is normal for it to get hot after a relatively short period. Have you guys had any problems with overheating?