Simon works to make sure that the medical teams have electricity, equipment and somewhere to rest after dispensing medical treatment.
MSF, which has had a Dublin office for the last three years, has been sending healthcare teams around the world since 1971, with the aim of giving treatment when and where it is needed most. But there has been a cost and there are risks.
"I think maybe 28 MSF staff were killed since 2008," Simon said.
"Most of them would be local staff rather than ex-pats and there are dangers in places like Somalia where there are MSF projects.
"It is local staff that still face the most danger, there can be consequences for killing a European that may not be there if a local is killed."
While in the Congo his compound was robbed twice by armed gangs and base security can be a concern.
However, the risks have not stopped the charity's workers going into areas which have experienced conflict, trusting that their independence from governments will help protect them.
"Most people understand that we are there to help," Simon said.
Sometimes there can be an existing health infrastructure to work with and other times not.
In a well established project things can be simpler but Simon's most recent posting to Maitikulu was more basic.
"It was starting from scratch, installing electricity, constructing storage facilities, fixing generators which were old and tired and broken... all the very basic things you would normally take for granted," he said.
"When you go to the Ulster Hospital you walk in and are treated so you have no idea about the other things, waste management and disposal and hygiene, but they are all important and need done."
The digital age and email has made it easier to order supplies across a multi-language supply chain. But there are still low tech answers to some problems.
In his Northern Ireland homeland sucking diesel is a term used when things are going well, for Simon it became part of the ritual of siphoning fuel from drums into the tanks of the medical vehicles.
Aid workers tend not to get into that line of business to make a fortune and Simon's next move is to buy some land and set up home in Burundi, where the prices match his income.
"Hopefully it will be a good base for me to work around Africa from. There will certainly be much less of a commute, though I will still be coming back. Belfast will always be home," he said.
He has had malaria five times, but fortunately his proximity to medical treatment has meant it was simply dealt with. What he does means that other people will have the same chance of treatment.
from his projects and on it he explains why he chose humanitarian work.
"It's not selfless really. At the end of the day I want to sit back and know I've done something worthwhile," he wrote.
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