The deleterious effects of hyperthermia are well appreciated in able-bodied persons. However, the consequences of impaired regulation of normal body temperature on cognitive performance of persons with tetraplegia is not known. This study will provide the preliminary findings necessary for future work to design and explore physical and medical interventions to improve temperature regulation in those with tetraplegia with the goal of improved clinical care, health, and quality of life.

The proposed study consists of 1 visit during which 20 subjects (10 with tetraplegia, 10 controls) will be exposed to 81°F for 40 minutes and then 95° F for up to 2 hours. Physiological as well as psychological processes will be monitored in all subjects during the study for safety and to determine differences in responses to exposure to hot ambient temperatures

After a cervical spinal cord injury (SCI) the motor, sensory and autonomic deficits cause, among other detriments, a blunted ability to maintain a constant core temperature. Impaired thermoregulation leaves persons with tetraplegia more susceptible to hyperthermia than able-bodied persons (AB). There has been a paucity of work addressing the thermoregulatory responses of persons with SCI to hot ambient temperatures, and even less study addressing the effect of these temperatures on cognitive performance. The goals of this pilot study are: to improve our understanding of the thermoregulatory mechanisms of individuals with tetraplegia when exposed to heat and to determine the effect of impaired thermoregulatory mechanisms on cognitive performance during exposure to 35°C for up to 2 hours. In order to address our goals we have designed a study methodology which consists of comparing the physiological and psychological responses of the two study groups (tetraplegia versus AB controls) from thermoneutral (27°C) to hot (35°C) environments.

Inclusion Criteria:

1. Between 18 and 65 years of age;
2. Duration of injury ≥ 1 year;
3. Level of SCI C4-T1;
4. Euhydration (Subjects will be instructed to avoid caffeine and alcohol, maintain normal salt and water intake, and avoid strenuous exercise for 24 hours prior to study); and
5. Age (± 5 years) and gender matched AB control group.

Exclusion Criteria:

1. Known heart and/or blood vessel disease;
2. High blood pressure;
3. Kidney disease;
4. Diabetes mellitus;
5. Acute illness or infection;
6. Dehydration;
7. Pregnant women;
8. Untreated thyroid disease, and
9. Broken, inflamed, or otherwise fragile skin.

10 subjects with tetraplegia (SCI, C4-T1), ages 18-65 years old and 10 age- and gender-matched, able-bodied controls will be accepted for participation.

Adverse events were reported within five business days to the VA's Institutional Review Board (IRB) via an Adverse Event form and were also included on the Adverse Events log on the annual continuing review application in accordance with VA IRB policy.

Adverse event data were collected throughout the entire course of the study, i.e. from 2012 to 2015.