चिन्तामपरिमेयां च प्रलयान्तामुपाश्रिताः। कामोपभोगपरमा एतावदिति निश्िचताः ॥

chintām aparimeyāṁ cha pralayāntām upāśhritāḥ kāmopabhoga-paramā etāvad iti niśhchitāḥ

Giving themselves over to unmeasured thought whose end is death, regarding the gratification of desires as the highest, feeling sure that this is all,

In plain words: Krishna continues: such people are filled with endless worries that last until death. They think satisfying their desires is the most important thing and are sure that nothing else exists.