I have used ATM machines  when I travel since 2010 and I’ve personally never had a problem. In all the projects that we’ve had I can count on one hand the number of volunteers that have had trouble with drawing on their cards. That’s not to say someone  will have trouble from time to time. What we suggest is that you take over $100 worth of your own currency, converted into local currency when you land, so you’ve got that on you as you fly in. As soon as you land at the airport, withdraw some money from the ATM. If there is an issue with someone’s card, and you absolutely can’t get cash out the project leader will loan some money for what you need for the week and It will be sorted out later.