searching story: men in 'tank' living in VR are waken up because of new Ice age coming

Question

Many years ago I read this short story:

(most of) humanity lives in tanks/machines that feed them. They have a rich social live. They hardly remember/realise this is not the 'real' live.
The main character (living in a tank) experiences strange failures and disturbances. Slowly he realises that something in the 'real world' is causing trouble. In the end he opens up his tank and climbs out.(that is amazing; because he hardly has any muscles left).
It appears that a group of humans (that are not living in the tanks) are opening the tanks to 'free' the people inside. This is because a new Ice Age has arrived and glaciers threaten the caves where the tanks are in.
However: the main character has lived way too long in the tanks and is physically to weak to be rescued. The main character crawls to the opening of the cave and finally sees the real world again: a dark night with stars and glaciers approaching.
There he (peacefully) dies.

Any idea of the title and/or wiriter? I read it in Dutch; and I am not sure if I choose the right words to describe the plot...

Answer 1

Cocoon by Keith Laumer

People spend their lives floating in tanks with virtual reality displays over their eyeballs and food tubes in their mouth. Protagonist is working (in the "office" TV channel) when the channel is interrupted by a bearded person warning that glaciers are burying the city. He protagonist's tank malfunctions so he crawls out, muscles too weak to walk. The bearded guy and crew find protagonist and tell him to wait for a robot to put him back in his tank.