I have been growing HeLa to 90-100% confluency in 12 well dish, prior to subjecting them to heat stress at 43 degrees Celsius for 1.5hrs in a water bath. Unlike HEK293T, the HeLa cells lose adhesion and drastically change into detached, rounded cells which do not re-adhere even during recovery (post-stress). I need suggestions on how to prevent cells from detaching and whether HeLa Kyoto specifically might be more prone to heat stress induced detachment from dish.