All day today i feel hot, then cold, then hot, then cold and so on. what would do this? the only thing i did different today was take claritin (loratadine) d.

Virus vs side effect: Time will tell. Infection, side effect or menopause; but most likely would be viral infection. Chills would be an unusual side effect for Claritin (loratadine) d, but if you aren't sick, just don't take any more Claritin (loratadine) d and see if it goes away. After a few days, you could take one again and see if it recurs. That's how to figure out if it is a side effect when the symptoms are not dangerous.