Should i be worried about sudden pinches or burning sensation on my body(mostly boobs and arms)and feeling like i'm hot (but my temperature is normal)?

Many possibilities: From a muscular problem of the chest or arms, to some sort of medical illness (viral illness, problem such as thyroid dysfunction, other hormone problems among others). Recommend seeing a doctor licensed in your area for examination to help pinpoint the likely cause and if remains unclear they can run tests.

Likely hormones: Hormone check. Examination of areas affected to considered. could be Raynaud rxn as well, if wet or cold exposure.