A major component of this study is to test a novel application for a safe, non-pharmacologic, cost-effective intervention that is already in use in clinical practice - using cool dialysate during hemodialysis to help stabilize the sleep/wake cycle of chronic hemodialysis patients. We will also evaluate its effects on selected sleep-related physiologic, psychological, behavioral, and general health outcomes.

Preliminary results demonstrate that, after one treatment, using cool dialysate instead of warm dialysate markedly normalized the rhythm of body temperature and improved indices on nocturnal sleep quantity and quality. Therefore, a major component of this study is to test a novel application for a safe, non-pharmacologic, cost-effective intervention that is alreay in use in clinical practice - using cool dialysate during hemodialysis to help stabilize the sleep/wake cycle of chronic hemodialysis patients. We will also evaluate its effects on selected sleep-related physiologic, psychological, behavioral, and general health outcomes.

To test the efficacy of this intervention, a randomized, single-blinded, pretest-posttest, control group design is being used. The major independent variable is dialysate temperature. The major dependent variables are measures of sleep, body temperature, rest/activity patterns, and general health outcomes.

Inclusion Criteria:

• All races, cause of renal failure is diabetes, hypertension, glomerulonephritis, or polycystic kidney disease; ability to read and write in English; clinically stable.

Exclusion Criteria:

• Current use of sleeping medication; history of alcoholism or drug abuse; brain disease; severe hypertension; severe heart disease; low functional level