Does a lower than normal temperature indicate illness?

[hellhasnofurylikeahungrywoman]

My normal body temp is around 36.6°, today it has sat around 35.3-35.5 and I feel washed out but not really ill iykwim. Just wondering if a low temp could be the cause of the washed out feeling.

Have you had your thyroid checked out?

No I haven't but I have lost around 5lb in the last few days. Can it be indicitive of thyroid problems?