Research material: The postcard Heimans sent the evening he died.
‘Today it is very hot, it has been exhausting and I did not feel well at all. If I feel the same tomorrow, I will be home the day after. It is too hot and too far.
Source: Eli Heimans, “Laatste postkaart uit Gerolstein”, , Heimans & Thijsse stichting, Artis Library, Amsterdam.