"doing a lot of brain work"

[montevjl]

Can anyone help with the following concept:
What is the best expression to indicate that people are doing a lot of thinking to solve a problem, ie : a group of scientist are working over overnight, "doing a lot of brain work" to find a solution to a forthcoming disaster.
Tks

 

[Stilo]

Possibly use the word 'Brainstorming'?

 

[David L.]

'burning the midnight oil' doesn't convey the sense of intensity and urgency implied if a catastrophe is looming