The Special Housing Unit is used for administrative detention and disciplinary segregation. From the Code of Federal Regulations (28 CFR Sec. 541 et seq):

Administrative detention status is an administrative status which removes you from the general population when necessary to ensure the safety, security, and orderly operation of correctional facilities, or protect the public. Administrative detention status is non-punitive, and can occur for a variety of reasons.

There is no television or radio or contact with other inmates. Detainees are on 23 hour a day lockdown, 5 days a week. They are allowed 1 hour of excercise if they are able to take it in a maximum security setting. The other 2 days they are on 24 hour lockdown. Showers are limited to three times a week.

28 CFR 541.23 lists the reasons one can be put in the SHU. They include:

(a) Pending Classification or Reclassification. You are a new commitment
pending classification or under review for Reclassification.

...[c]; Removal from general population. Your presence in the general population poses a threat to life, property, self, staff, other inmates, the public, or to the security or orderly running of the institution and:
(1) Investigation. You are under investigation or awaiting a hearing for possibly violating a Bureau regulation or criminal law.

28 CFR, 541.27, provides for placement of a detainee in administrative detention status if staff believe:

“[b]ased on evidence, [the inmate’s] safety may be seriously jeopardized by placement in the general population.”

If the detainee is placed in segregation on this basis, he is entitled to a hearing “within seven calendar days” to determine if there are reasons justifying the placement. 28 FR 541.27(d).

The same rules are applied to inmates placed in the SHU for administrative reasons as those there for disciplinary purposes.

§ 541.32 Medical and mental health care in the SHU.

(a) Medical Care. A health services staff member will visit you daily to provide necessary medical care. Emergency medical care is always available.

While the Constitution does not provide for comfortable prisons, it does require humane prisons and adequate medical treatment.

With all of his injuries, who is monitoring Tsarnaev for infections?

Contrary to some news reports, Devens is not a minimum security facility. All six of the BOP's medical facilities are administrative facilities, meaning they house all security levels. Devens provides Level 3 and 4 medical care, but it is not a hospital.

There are more than 1,000 inmates at Devens. While there is an adjacent minimum security camp, it only houses about 120 inmates, and Tsarnaev is not one of them.

40% of the inmates at Devens are sex offenders getting treatment. There are lifers and violent offenders.

There have been many lawsuits filed against Devens for inadequate medical care and negligence. Jeffrey Barrett filed a complaint in October, 2012, alleging gross negligence due to his infections being untreated. His hand, wrist and part of his forearm had to be amputated when they finally took him to a hospital. (Case No. 12-cv-11726.)

Barrett suffered from kidney failure before being imprisoned. He had been getting hemodialysis through a central line. When he was taken into custody, they put him in Orangebury, South Carolina which decided to discontinue the central line and instead implant a fistula into his right arm.

The day after the surgery, they handcuffed him, put him on Con Air and flew him to Devens. At Devens, he was placed in the SHU. Here's one page of what he says happened at Devens. Shorter version: He was left for 5 days in the SHU with no medical treatment. They didn't even change his wound dressings. On the 6th day, bleeding profusely, they rushed him to the hospital. The infections and necrosis of his hand (gangrene)were so severe, doctors had to amputate.

According to Barrett's complaint, detainees in the SHU are confined to their cells 23 hours a day on Monday to Friday and 24 hours a day on weekends. They eat, sleep, bathe and use the toilet in the same small cell.

What is required for inmates needing medical care in the SHU (BOP Program Statement P6031.01)

13. SPECIAL HOUSING UNITS (SHU)

All Health Services Units will have procedures and control systems to ensure continuity of medical and psychiatric care and treatment for inmates housed in SHUs. Health care staff will be informed immediately when an inmate is transferred to SHU. Procedures will be determined locally.

Local procedures will include at least the following:

• Protocols to provide for the assessment and review of inmates transferred to SHU.
• A health care provider will make daily rounds during the “lights on” period, except in extenuating circumstances. These rounds will be announced and recorded on the Special Housing Unit Record (BP-A0292).
• A mechanism describing how SHU inmates will notify medical staff of their need for health care.
• Daily rounds to triage urgent requests for care (should be accomplished by the same staff member who conducts the morning pill line in SHU, typically an RN/LPN/LVN).
• Procedures for follow-up care by an MLP or physician. All SHU inmate encounters, including medication refills or dispensing of over-the-counter medications, will be documented in the inmate health record

Here's a list of the various BOP medical care program statements.

Another of Barrett's claims: The staff at Devens inaccurately told his mother he had died. After getting that news, she died.

Then there's Devens inmate Aktham Abuhouran who contracted Methicillin Resistant Staphylococcus Aureus ("MRSA"), a highly contagious staph bacterium, after being transferred to an area of FMC
Devens that was less sanitary. His story is horrifying. The Judge, in ruling on his complaint, described the medical facilities at Devens (Case No. 07-40201):

FMC Devens, a federal prison that houses male prisoners requiring specialized medical care and contains three separate housing units for inmates: the "Long Term Care Unit" ("LTCU"), P-2 units and N-2 units.....

LTCU resembles a hospital where inmates bathe frequently with the assistance of orderlies, are continuously monitored, have unrestricted access to medical care and which is cleaned frequently.

P-2 houses prisoners who need less medical care. They use communal showers and are responsible for cleaning their own rooms and laundering their own linens (in shared washers and dryers), but they also enjoy unrestricted access to medical care. Mattresses in P-2 are cleaned infrequently, if ever.

N-2 is for prisoners who are healthier than those housed in the other two units but still require medical attention. N-2 prisoners live in two-man rooms, and like P-2 bathe in communal showers and are responsible for cleaning their own rooms and laundering their own linens. They do not have access to unrestricted medical care but must submit a sick call which typically results in a medical appointment a few days later. They must travel to the FMC mess hall to receive meals, whereas prisoners in the other two units have their meals delivered to them. N-2 mattresses are also cleaned infrequently, if ever.

Also tragic is the story of Michael Black, a severely obese paraplegic. On Lexis.com, there are 128 rulings in lawsuits over medical care at Devens.

In 2011, the Feds put out bid solicitations for mortuary services at Devens. It said there are approximately 25 deaths a year.

Tsarnaev has not been convicted of a crime. He is entitled to adequate medical care and humane conditions. Prolonged solitary confinement in the hole is not humane. His public defenders are 40 miles from Devens. Due to sequester furloughs and cuts, they will have even less time to spend on his case than they normally would. While the court will appoint additional counsel for him, that hasn't happened yet.

If Tsarnaev doesn't receive adequate medical care, and ends up with infections or worse from his shooting injuries, it will be a black stain on the Bureau of Prisons and the nation.