Alright, I will be the first to admit that the heat in Rome on some days is insane, and will make you feel the same way. Simply standing still under the sun will make you sweat and you will want to throw under a scooter the tour guides with flags and pompoms hearding groups of what seems to be thousands of people with umbrellas and headsets walking towards you but looking at anything but in front of them until one of them evidently bumps into you and you get soaked in their sweat.
Keep calm. That is the point you vow never to pass the Trevi fountain before midnight and say ciao to the Pantheon and Navona in September.
On the flip side Rome throws its arms wide open for summer festivities! Below along the Tevere is lined up with bars and places to eat, tvs to watch the games, the island becomes a cinema, fabulous rooftops all over the city open up, a bar on top of Gianicolo will lead you to a drink taking in the most spectacular view of Rome, the gay village is partying, open air concerts in ancient ruins (hello rolling stones), unlimited parks with villas and ponds and the beach is only 40 minutes away. What more could you ask for?