How to prevent the Heap memory from exhaust ?

Hi all, 

Sorry if this is a side topic compared to this forum main scope, but I hope couple of us will benefit from it :

What is the best practice (in Fortran-90) to prevent the heap memory from exhaust (in Linux) ? In general, what is the best practice ''memory model'' when coding an average code (in complexity and size) in Fortran-90, are there any special guidelines ? For instance, I have read that using multiple times a subroutine which allocates / deallocates local arrays can exhaust the memory. I currently experience heap exhaustion in my code and I'm not sure how to tackle it.

Thanks in advance for your comments,

Jack.