Potential teething

My LB is 2 and a bit. He had a high temp all last night and then a fever this morning. Hes off his food and has done a couple of really soft poos. He has been chewing his fingers a lot so wondering if it’s teething or something else. Any advice? Were really paranoid as he suffers with febrile seizures so any illness, we’re so anxious so any advice would be amazing