Cold and Heat Investigation to Lower Levels of Depression

This study is investigating whether whole-body heating (like a sauna) or cooling can reduce symptoms of depression, comparing different temperature-based therapies to see which works best. **You may be eligible if...** - You currently have depression or do not have depression (both groups are being studied) - You speak English or Spanish - You are able and willing to attend all study visits and follow study instructions **You may NOT be eligible if...** - You have had a bad reaction to heat, cold, or infrared exposure in the past - You take medications that affect your body's ability to regulate temperature - You are pregnant, breastfeeding, or planning to become pregnant during the study - You currently have active thoughts of suicide with a plan, or have made a suicide attempt in the past 6 months Talk to your doctor to see if this trial is right for you.