not sure what to do

Maybe.  You must be BFing.  Did you eat something weird??  How did he do with his other feedings?  Did you switch sides during that hour feeding?  Are you certain he emptied the first side before switching?  My nephew used to throw up a ton whenever his mom ate dairy so once she cut back on it, he improved.

I wouldn't worry about his temperature.  It is within normal range (95.9-99.5).  I would just watch him over the next couple of hours and see how he acts/eats etc.  Does your Dr. or Hospital have a nurses line?   I always call them if I am unsure about my son's health. 

Was he in pain or did he just throw up?  I wouldn't worry too much, unless he exhibiting signs of discomfort or is failing to gain weight.  Also, exorcist style PROJECTILE vomiting warrants a call to the ped, otherwise, he should be ok, just keep an eye on him and if his temp exceeds 100.4, you need to call the ped.

 he could have needed to burp. when they eat alot and havent fully burped it can make them throw up

He wasnt in any pain he acted just fine afterwards as well.

I wouldn't worry about it then, unless it continues and is copious amounts.   (Take a tablespoon of milk and splash it on the counter and notice how much it LOOKS like.)  It can LOOK like a lot of spit up when, in actuality, its a tablespoon or less.  Just keep an eye on him.

97.1 is okay but I would try to keep it above 97. Maybe swaddle him tight the next time or put a hat on his little head. His temp should NEVER drop below 97 because this could cause problems. In nursing school we were taught to keep the temp above 97.5 If he keeps throwing up I would call the pedi. Sorry, hope this helps.

I wouldn't worry about it too much. I would call the pedi just to feel more comforted but my pedi always said she never worries about throw up unless it's VERY often or unless it's projectiled.

little ones are learning how much they can hold and they often dont stop if they are full which can cause him to throw up. as long as hes acting  fine just keep an eye one him and remember that a temp of 98.6 is normal. 

did he burp at all in that hour? if not, he might have had a gas bubble that milk got caught on top of...