Kleśada. This material body is kleśada. Kleśada means always giving us trouble, always giving. Kleśada āsa. So one should always remember that "I have got this material body, which is suffering heat, cold, mātrā, sukha, duḥkha, happiness, distress." Why? Because this material body...
- mātrā-sparśās tu kaunteya
- śītoṣṇa-sukha-duḥkha-dāḥ
- āgamāpāyino 'nityās
- tāṁs titikṣasva bhārata
- (BG 2.14)
So long you have this material body, bhūmir āpo 'nalo vāyuḥ khaṁ mano buddhiḥ (BG 7.4), then... Material world means suffering. You cannot avoid suffering. But the endeavor is how to get out of suffering. That is called struggle for existence.