Before there was a vaccine for polio, when spring was coming, it was always a race against time, because spring brought summer and summer brought the stifling hot weather when the polio virus spread most quickly. Summer also brought the flies and it was thought that the virus might be spread by them. Often people suffered from the heat with their windows closed because they could not afford metal screens for their windows and of course there was no air conditioning at that time. So summer, a time that would normally be anticipated particularly in parts the world where winters were severe, it was feared more that enjoyed. No wonder kids were frustrated when they were not allowed to do the fun things normally reserved for summer holidays.