Can glaciers be melt in normal weather (30℃+) and/or intentionally heated?

yes, the ice melts just like any ice will melt when exposed to heat. Normally, glaciers are like rivers of ice, with heads (beginnings) up in places where it is colder most of the time, so snow that falls every year and some never gets to melt (not long enough warm times to do that) so it just keeps adding, year after year. Their "mouths" are down in the lowlands where it is warm enough, long enough during the year, to melt the ice about as fast as it flows down from up above. But some melting occurs even up where the ice stays year round, and that water tends to sink into the glacier and form rivers inside the glacier or at the base of the glacier.

The mass of ice is simply too big to warm it on purpose. Glaciers can run to thickness of a few kilometers in places, and that is a large amount of ice.