Looking to shake its school away from its investment in fossil fuels, Harvard University environmental activist group Divest Harvard is in the midst of “Heat Week,” a series of planned demonstrations that began on Sunday and are expected to last through Friday.

According to Divest Harvard, the group and its supporters are seeking to convince Harvard to divest its $35.9 billion endowment from fossil fuel sources.

Recent reports from investment firm Trillium Asset Management revealed that Harvard could have saved around $21 million without fossil-fuel investments during the time since the divestment campaign began in August 2012.

More than 250 faculty members have signed a petition in favor of divestment, while more than two-thirds of the undergraduate student body also voting for the university to divest.

Now part of the way into “Heat Week,” a multitude of sit-ins, blockades and other demonstrations have already been felt around campus.

Sunday, April 12

“Heat Week” actions began first with more than 50 organizers — including Bill E. McKibben, environmental activist and leader of environmental group 350.org — discussing plans for the week at First Parish church in Cambridge.

A few hours later, more than 150 protesters began to gather outside Massachusetts Hall — which houses many of Harvard’s top officials, including President Drew G. Faust.

Starting at around 7:30 p.m., protesters began blocking the main entrance to Massachusetts Hall, interacting cordially with a growing number of Harvard University Police Department officers.

McKibben and former Colorado Sen. Tim Wirth addressed the crowd during the protest.

Monday, April 13

Protesters continued their blockade of Massachusetts Hall Monday morning, but also expanded their efforts by swarming the Harvard Alumni Association office on Mt. Auburn Street—with a dozen alumni planning on spending the night in a show of dissatisfaction with their school’s investment choices.

Some protesters blocking Massachusetts Hall Sunday night remained outside the office during the night, waking up around 6 a.m. in order to continue stopping university officials from entering the building.

No officials managed to enter Massachusetts Hall as a result of the protests, with many relocating to neighboring locations for the day.

Protesters at the Harvard Alumni Association office wrote up pledge cards in support of a fossil-free fund, with the condition that the university will only earn the donations if it indeed divests from fossil fuel corporations.

Demonstrators at the office attempted to set up a meeting with Alumni Association officials, but were not given an opportunity to do so. In response, 12 protesters motioned to stay in the office overnight in order to show their dissatisfaction with the HAA’s decision to avoid talks.

Tuesday, April 14

Once again, university officials were denied entry into Massachusetts Hall Tuesday, as protesters continued to block off the main entrance.

In the early morning hours, however, around 25 Divest Harvard members began blocking the main entrance to University Hall — which holds the offices of leaders within the Faculty of Arts and Sciences. Multiple university staff members were turned away from the building, along with two custodians.

Protesters eventually left University Hall by around 10 a.m., but by that time, many university leaders were already forced to move to other areas in order to work.

Meanwhile, protesters continued to stand firm within the Harvard Alumni Association offices — still looking to discuss divestment plans with university officials.

Wednesday, April 15

After spending almost two days trying to establish talks with university officials, protesters finally left the Harvard Alumni Association office Wednesday morning with no luck in terms of speaking to leaders.

While protesters expected a much more uneventful day on Wednesday, campus workers — toting a police escort — were once again denied entry into Massachusetts Hall.