29 yrs old male with Hx of substance abuse presented to ER wi | sᴘᴏᴛ ᴅɪᴀɢɴᴏsɪs

29 yrs old male with Hx of substance abuse presented to ER with confusion and fever for 2 days, patient recently admitted for hallucinations received Rx and discharged, O/Ex Bp:150/100,T°:38.9 and muscle rigidity of all 4 limbs, spot diagnosis?