1749 he traveled to Palestine to document flora and fauna. 1751 he travelled via Jaffa to the holy country where he collect some natural material but died before he willed travel home. Hasselquist has probably tuberculosis already at his departure.
Left documentation
Vires Plantarum - Växternas krafter 1747 och Iter Palestinum - Resa till Heliga Landet, 1749-1752,that was given posthumous by Carl von Linné 1757.
Notable
He became member of sciences-society in Stockholm and Uppsala.