<p>This study uses a cluster dynamics (CD) model to investigate the evolution of irradiation-induced defects in tungsten (W) at high temperatures. Simulations were carried out at 600, 800, and 1200 ℃ up to 0.2 displacements per atom (dpa) to study the behaviour of dislocation loops, voids, and C15 clusters. The model results are compared with experimental data for verification. Important physical mechanisms such as loop coalescence, recombination between self-interstitial atoms (SIAs) and vacancies, and vacancy clustering are included. Loop formation energies for 1/2 &lt; 111 &gt; and &lt; 100 &gt; types are calculated using dislocation elastic theory. At higher temperatures, increased defect mobility promotes the coalescence of smaller defects into larger ones, resulting in fewer but larger loops and voids. The model captures this trend well, showing an initial increase in loop density at low doses followed by a decrease due to absorption at sinks. 1/2 &lt; 111 &gt; loops are more abundant, and larger at all temperatures due to their lower formation energy. &lt; 100 &gt; loops are less common, and they mainly grow by absorbing smaller 1/2 &lt; 111 &gt; loops. When the C15 cluster collapse is included, the density of both loop types increases, especially that of &lt; 100 &gt; loops, and the number of voids decreases. The model also shows that SIAs tend to move from 1/2 &lt; 111 &gt; to &lt; 100 &gt; loops, promoting the growth of &lt; 100 &gt; loops.</p> Graphical Abstract <p></p>