The Health Minister says we could end up in a "very dangerous place" if people move ahead of the roadmap in easing Covid-19 restrictions.
From Monday, construction sites and hardware stores will be among the businesses allowed to operate again.
Phase two will be considered in three weeks, and will look at the possibility of people being allowed to travel up to 20km.
But Simon Harris says people need to be careful.
“We need to make sure people don’t get ahead of the plan and it’s entirely human nature,” he said.
“It’s been tough and challenging beyond belief for many people.
“But we do need to make sure people don’t now try to jump ahead of the plan.”
Mr Harris said if we get into the mindset of “if it’s safe to this, that and the other, sure maybe it wouldn’t be any harm if I did a little bit more” the country will end up in a “very, very dangerous place”.
Meanwhile, Mr Harris said it will be up to the Attorney General to decide what punishment people face if they break self-isolation rules after entering the country.
It is now mandatory people fill in a form detailing where they will be quarantining for two weeks due to Covid-19.
Earlier this month, it emerged more than a third of people didn't do it when arriving into Dublin Airport.