First off, what's causing hte hot spot? Matted fur? Fleas? An allergy? Put some advantage on the dog to make sure he doesn't have fleas. Then get a tube of neosporin (no itch) ointment and put a dab on the hot spot. It shoudl start clearing up in a day or two.
Clip the hair away from the spot and apply Penaten cream. This is what I use on my Chows which are very prone to hot spots. As was already said you need to find out what the hot spot is in response to.
We treat hot spots by shaving hair away from the immediate area. Preferably a complete bath with anti-bacterial shampoo, or good scrub and rinse of immediate area with solution like betadine scrub. Clean and dry very well... then at our animal hospital we usually apply Neo-Predef powder applied liberally and then have area just kept clean and dry. This treats the symptom.......... It is important to get at the root of hot spots, they are almost always caused by excess undercoat or matted hair and dirty skin that is unable to "breathe". I also see hot spots develop on dogs with good coat condition normally, but that are frequent swimmers. Fleas can be a real instigator, but the skin problems we see from fleas aren't usually hot spots but flea allergy dermatitus. Hot spots are generally "light colored spots of hair loss surrounded on edgy by reddish irritation that are quite moist/oozy on the surface. FAD is usually flaming hot pink/red skin with open sores and varied degree of scabbing usually much worse at base of tail and feet then progressing toward the front of the dog. Hot spots generally appear randomly on the dogs.... anywhere that the hair is thick. These can appear together on the same dog also..... skin problems can really make a pet miserable so once you track down the cause it is much easier to prevent in the future. Good luck with your kid.