My mom who is 56 got bit yesterday while at the store.Its red,swollen,itchy, and feels hot. What kind of bite is it? When it happened she felt hot and cold at the same time,and felt weak,like she was going to pass out. At that time we didnt even know she had been bitten. Should we be worried? Does she need some kind of medicine for this? She also felt nauseated... its a pretty huge knot!