The purpose of this study is to learn how whole-body hyperthermia (achieved in a sauna) may work to decrease feelings of depression and anxiety. We know that this intervention works in adults with depression, but we do not know how it works. We also want to find out if postpartum women will find this intervention acceptable, and whether the way it works may be different in postpartum women from other people. 

This research study is being done because we do not have very many treatments for depression or anxiety that work quickly. If we could learn more about how whole-body hyperthermia works, we might be able to develop other treatments to help people with depression or anxiety get better quickly. 

Participants will come to the Weill Cornell main campus on the Upper East Side once for about half a day (approximately 4 hours). They will answer surveys about their psychological health and then will participate in a sauna session, meant to heat their internal temperature to 38.5C (101.3F), which will last up to two hours. The sauna session involves lying down under a dome wearing only underwear or loose fitting clothing and with a small, flexible thermometer in the rectum or vagina to measure core temperature. Participants heads will be outside the sauna dome, which we will cool down with ice and provide water and other drinks throughout the procedure.

When the session is over, participants will be covered with towels for about 30 minutes while the body cools down. A member of our staff will be present at all times, and a doctor will be available close by.

After the sauna session is over, participants will answer additional psychological survey questions using an electronic link 3 times – 2 weeks, 4 weeks, and 6 weeks after the sauna session. They will also meet with a member of the study staff by Zoom for additional psychological questions 6 weeks after the sauna session.

Total study participation will last approximately 2 months.