Read James Brooks‘ answer to What does throughout mean in this sentence, “The organization was first-class, with medical volunteers on standby throughout, and drinks stations every few kilometres of the route.”? on Quora
Throughout has two meanings:
- In every part of a place
- From beginning to end of a specific time (such as an event)
In this context the word throughout is a bit ambiguous. Either meaning would fit in this context. This might be on purpose; the author of the sentence might mean both that they were available from beginning to end as well as they could be found anywhere (rather than concentrated in one area).
If only one thing was meant, it would depend on the situation. If there were only a few medical volunteers (so it was impossible that they were everywhere at once), then it could only mean that they were available from beginning to end. If there were many medical volunteers (and the author wants to only use one meaning) then they would be referring to them being found everywhere.