An epidemic of chronic kidney disease is occurring in laborers who undertake physical work outdoors in hot conditions. The reason for this is largely unknown, but may be related to kidney dysfunction caused by increases in body temperature and dehydration that elicit oxidative stress and inflammation in the renal tubules. The purpose of this study is to determine whether hydration status modifies the development of renal oxidative stress and inflammation.

Inclusion Criteria:

• Men and women
• 18-44 y old
• Body mass index ≤35.0 kg/m2
• Self-reported to be healthy

Exclusion Criteria:

• Not within defined age range
• Estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m2
• Body mass index >35.0 kg/m2
• Current or history of any renal disease, heart disease, stroke, immune or autoimmune disease, and/or gastrointestinal disease/surgery
• Hypertension during screening (systolic blood pressure >139 or diastolic blood pressure >89)
• Using medications that blunt the physiological response to exercise (e.g., beta blockers)
• Prescription medication with a known side effect of impaired temperature regulation or fluid balance (e.g., diuretics)
• Positive pregnancy test at any time during the study or breast feeding
• Current tobacco or electronic cigarette use or consistent use within the last 2 years
• Answered "Yes" to any question on Page 1 of the PAR-Q+.