The visit of Terezin itself is so stressful that I don't think that an additional visit to Lidice on the same day can be recommended. And in Terezin you can spend quite 3-4 hours, because the sites are not concentrated in one place. The natural beauty and a peace of Terezin contrasts so much with the horrows that happened there 60 years ago!

Sincerely, Alex Elbert Jerusalem Israel