The persona is suffering from AIDS and as it can be seen, his body is slowly deteriorating. He “wake[s] up cold” in the middle of the night, unable to contain the pain and restlessness – “Night Sweats” – and begins remembering his past when “[he]…prospered through dreams of heat”, implying a past of promiscuity and how now he “Wake[s] to their residue/ Sweat, and a clinging sheet.” His body is becoming just a “residue”, of what it was before, or what he thought his body used to be. “My flesh was it’s own shield/ Where it gashed, it healed.” and for this reason, he failed to take care of it because he believed it could take care of itself regardless and so he became too careless with how he treated it.
While he was sure his body was invincible, he took the carelessness too far, he “grew as [he] explored/ The body [he] could trust/ All the while [he] adored/ The risk that made robust/ A world of wonders in/ Each challenge to the skin.” He was unable to stop and “adored” being promiscuous so much and he thought, since he could still “trust” his body, why not take it a little further? He found a thrill in every “risk” taken and it became addictive with “Each challenge to the skin.” Like smoking a cigarette, knowing very well, or ignoring the fact that, by doing so he was increasing the risk of contracting what he ends up with now.
The irony is that he can barely take care of his body which can now barely take care of him and so they are both “reduced and wrecked.” He has now become less than he ever was – “reduced”.
Having enjoyed all that, he “cannot be sorry” over his experiences, but he does say this poem with a tone of regret as to how his body ends up. As he deteriorated, “[his] mind reduced to hurry” He realizes that he could be reaching the end of the road and he is living too fast. Something that happens as we approach the end. His “given shield was cracked.” He cannot contain “shield [his body] from/ The pains that will run through [him]” but even then, he is “Hugging [his] body to [himself]” as a defence mechanism from the pain that comes and then he realizes the “hands [are not] enough/ To hold an avalanche off.”
The persona uses the word “shield” a lot in the poem, emphasizing on protection and his need for protection. When he has it, he failed to take care of it or appreciate it and now he loses it and tries to give himself some protection but is unable to do so. The magnitude of the pain also is very high as attributes it to “an avalanche.”
The sixth stanza to part of the seventh stanza, “I have to change the bed/ But catch myself instead/ Stop upright where I am” could also imply his trying to stop himself from risking any further. Just as he is about to go sleep with another person – “change the bed”, he “catch[es] himself instead” before taking another risk.