Funny how everyone seems to be concerned for his physical safety. As if he is going off to war and needs to fear the people around him. Statistically rescuers, even in the worse third world conditions, are far safer from physical violence than many in urban areas within the US.

The major short term risks are exhaustion, psychological trauma, back strain, temporary digestive issues. Depression, nervousness, PTSD, and long term-respiratory issues associated with concrete dust and undifferentiated contaminates are common long term issues.

I wish him well but my advice would be to make sure you sleep any time you get half a chance, eat and drink regularly. Even if you don't feel like it. Haiti is tropical so wear a long-sleeve shirt, hat and lay on the sunscreen heavily. Stay hydrated. Pace yourself. Rest any chance you get.