I had a friend which the same thing happened to him. He went camping with friends and one morning, he got a headache. But he thought nothing of it and went home to sleep before go to work.
His dog licked his face and woke him up. He saw himself in the mirror and his face swelled up like beach ball and pain in one ear. He went to hospital and the doctor found a brown spider (male widow spider with no red hourglass spot). He was lucky that his dog woke him up in time becuz the brown spider is poisonous and can kill him.