People hang signs facing the Metropolitan Detention Center in Brooklyn on Feb. 4 to support inmates who were reportedly held in unheated cells as temperatures plummeted. (Justin Lane/EPA-EFE/REX/Shutterstock)

Jennifer Lackey is the Wayne and Elizabeth Jones Professor of Philosophy at Northwestern University, the director of the Northwestern Prison Education Program and a Public Voices Fellow through the OpEd Project.

A brutal arctic cold wave, which saw temperatures plummet to as low as -56 degrees Fahrenheit and caused at least 23 deaths, has passed for most Americans. But many of the men and women incarcerated in the United States continue to suffer from the weather in shockingly deplorable conditions. Their recent plight is only the most recent manifestation of a much larger problem.

Nelson Mandela, who himself spent 27 years behind bars in South Africa, famously said, “No one truly knows a nation until one has been inside its jails. A nation should not be judged by how it treats its highest citizens, but its lowest ones.” By Mandela’s standard, the United States is not faring well.

During the cold snap, 1,200 prisoners were left sick and frantic in freezing cells in Brooklyn’s Metropolitan Detention Center, a federal prison. Despite the frigid conditions, they were reportedly denied access to extra clothing and blankets. The inmates were left to bang pots and pans on their cell windows to signal their distress.  

Unfortunately, these appalling conditions are not uncommon.

The American Civil Liberties Union recently filed a class-action lawsuit accusing the Rhode Island Department of Corrections of housing prisoners in cells with no heat, even as temperatures dropped to 1 degree.

At least 23 people have died behind bars in Texas since 1998 due to extreme temperatures; a recent lawsuit alleges that the Texas Department of Corrections continues to deny Dallas prisoners protection from dangerous weather conditions.

And a federal lawsuit in Louisiana last year revealed that prison staff punish suicidal and mentally ill inmates by exposing them to extreme cold while being chained to wooden chairs.

Extreme weather conditions are only one tool the American criminal-justice system uses to send the message that inmates are less than human.

More than 60,000 Americans are in solitary confinement, spending 22 to 24 hours in their cells per day. Prisoners who are isolated for this number of hours, sometimes for decades at a time, are often driven to the brink of insanity. They experience delusions, engage in desperate acts of self-mutilation and attempt suicide at alarming rates.

Mental-health issues more generally are often ignored behind bars. About 2 million people with mental illness are incarcerated each year; at least 83 percent lack access to necessary treatment.

And nearly 25,000 prisoners report being subject to sexual harassment or assault while incarcerated in the United States, according to the Bureau of Justice Statistics. Transgender prisoners are particularly vulnerable to sexual violence.

The question we should ask here is how this dehumanization has been hidden from our sight — and why.

Prisons often occupy the “geography of nowhere.” They are found in unpopulated areas, far away from cities, so that both the facilities and the people they hold are invisible to most of the general public. We often hear talk of “removing” criminals from society; the location of prisons makes that rhetoric a reality.

Voter disenfranchisement is widespread in prisons in the United States. Only two states, Maine and Vermont, allow prisoners to vote while they’re incarcerated. Inmates quite literally are denied a voice in the democratic process. Elected officials can ignore them and their concerns, while the U.S. Census Bureau still counts incarcerated persons as “residents” of the location of the prisons rather than their home communities, shifting representation in Congress away from towns and cities with urgent needs.

Elections aren’t the only part of public discourse that excludes prisoners. They typically don’t have smart phones or Internet access, cutting them off from the use of email, social media and any other form of electronic communication. They can’t post photographs on Instagram that reveal the conditions of their cells or write Facebook posts about their treatment by correctional officers.

Brittany Foote, who was incarcerated in North Dakota for burglary, captured this feeling of isolation when she said: “It just feels like you get lost, you feel like they forget about you. You start to feel invisible, kind of like a ghost walking around here.”

If we don’t count the incarcerated as citizens because they are erased from our collective consciousness, we don’t have to account for our treatment of them when weighing our greatness as a nation. 

The first step toward ending this moral blight is a willingness to lift the veil of ignorance on the conditions of our incarcerated community members. We can see this in the recent actions taken by city and state officials in New York. In response to the protests and media attention regarding the conditions at the Brooklyn detention center, New York Mayor Bill de Blasio (D) sent a truck with blankets, hand warmers and generators to the facility. And New York Gov. Andrew Cuomo (D) called for an investigation, tweeting over the weekend, “Prisoners are human beings. Let’s treat them that way.”  

Recognizing that those in prison are our fellow humans and citizens reminds us of what we should have known all along: Criminal convictions should not lead to the denial of basic rights and human dignity.