May the friendly park keeper and her friends welcome enthusiastic young explorers to their park for a day of fun. It's the hottest of days in Big City Park and Ruairi, Billy, Dara and May are all feeling it. May makes sure that the children are well protected with sun cream and hats for their day in the park. They go exploring in the park and learn about how other animals and insects stay cool in the high temperatures. Billy has trouble keeping up in the heat until they learn how to avoid getting too hot. Ruairi prepares a healthy summer picnic and everyone enjoys his home made fruity ice lollies!