Indoor gyms and swimming pools will reopen from July 25 but Dr Hilary had a warning for those heading out.
“Well, we won’t know about the effects of easing lockdown for four weeks,” he explained.
“So we need to do the test and tracing to find out what’s going on, there will be a time lag, if you like, we haven’t got enough data yet to see what the effect of opening schools again will be.
“We know about the incubation period for the virus, we know how long it takes for symptoms to start, that’s why self-isolation has always been 14 days.”
Good Morning Britain airs weekdays on ITV at 6am.