Will my phone explode if i use it as a modem for long duration?

There's no free wifi over at the Perodua Service center. No choice but to remove and my sim card from the phone and plug in the Huawei 3g modem. Better also since i dont have to worry about the battery dying on me. Moreover, it's safer to use the Huawei modem when i need to blog for over an hour. The batteries in both my O2 and Nokia N82 have expanded due to the heat emitted from using the phones as a modem. I fear if i continue using them, they'll errr... explode. Will they? I seriously think so :p