I recently traveled to Italy in the middle of a record heat wave. It was beautiful, memorable, and physically much harder than I expected.
Part of that was the heat itself. Part of it was the way travel quietly changes the body’s usual operating conditions. Air conditioning is not as prevalent in Italy as it is in much of the United States. Days that look reasonable on an itinerary can become a long chain of sun, walking, crowds, standing, sweating, and trying to keep up.
Our trip included hot springs and saunas. We went on a boat excursion. We toured the Vatican. These were extraordinary experiences. They were also, I now realize, exactly the kinds of conditions that can be risky for someone taking lithium.
At first, I did what many people do when they travel: I explained away the warning signs.
I was dizzy. I felt nauseated. I was extremely tired and groggy, not just “vacation tired,” but heavy and slowed down in a way that felt different. I noticed muscle twitches in my hands. Still, I blamed jet lag. I blamed the time change. I blamed disrupted sleep, changes in my schedule, different meals, too much walking, and the ordinary stress of being far from home.
Those explanations were not irrational. They were just incomplete.
Eventually, I realized what was happening: I was on lithium, and my body was struggling in the heat.
Lithium has been incredibly important in helping me manage bipolar disorder. For many people with bipolar disorder, lithium is not simply another pill in the medicine cabinet. It can be a foundation. It can reduce the risk of mania, depression, hospitalization, and the kind of life disruption that bipolar disorder can cause. In my own life, lithium has been part of the structure that allows me to work, write, teach, travel, and function.
So this is not an anti-lithium story.
It is a respect-lithium story.
Avoiding Lithium Toxicity While Traveling
Lithium is effective, but it has a narrow therapeutic range. That means the amount that helps and the amount that can become dangerous are closer together than we might wish. Dehydration, prolonged sweating, vomiting, diarrhea, illness, changes in salt intake, and certain medications can increase the risk of lithium toxicity. The Food and Drug Administration-approved prescribing information specifically warns that dehydration from sweating and changes in salt and fluid balance can increase the risk of lithium toxicity, and it emphasizes maintaining a normal diet with salt and adequate hydration.
That matters in ordinary life. It matters even more in extreme heat.
A sauna is not just relaxing if you take lithium. A hot spring is not just a vacation indulgence. A long walking tour in a crowded, hot city is not just sightseeing. Each of these can increase sweating, fluid loss, fatigue, and physiological stress.
Even something as seemingly innocuous as the fact that food is not salted in the same way many American foods are salted can cause problems. If you suddenly reduce your salt intake, your kidneys reabsorb sodium to maintain balance. But because lithium and sodium are chemically similar, lithium is also reabsorbed. This raises blood lithium levels and increases the risk of toxicity.
And the symptoms can be easy to misread.
Nausea can seem like something you ate. Dizziness can seem like heat exhaustion. Grogginess can seem like jet lag. Muscle twitching or tremor can seem like too much caffeine, not enough sleep, or just being worn out. Unfortunately, lithium toxicity can involve symptoms such as nausea, drowsiness, dizziness, weakness, tremor, poor coordination, confusion, and more serious neurological symptoms.
People with bipolar disorder often become experts at monitoring themselves. We learn to watch our sleep, our energy, our mood, our irritability, our impulsivity, and our stress. We know that travel can destabilize routines. We know that crossing time zones can interfere with sleep.
But competence can turn into overconfidence. I knew travel could affect my bipolar disorder. I was less attentive to how travel could affect the medication that keeps me from spinning into manic highs or depressive lows.
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Planning Ahead for Travel on Lithium
The lesson is not that people taking lithium should never travel, never enjoy summer, or never go to Italy. The lesson is that lithium requires planning, especially when heat is part of the itinerary.
Before travel, especially to a hot climate, it is worth talking with your prescribing clinician about hydration, salt intake, warning signs, whether blood levels should be checked, and what to do if symptoms appear. Do not stop or change lithium on your own. But do ask for a plan. Ask what symptoms should prompt a call, an urgent care visit, or an emergency evaluation. Ask whether hot springs, saunas, strenuous walking tours, anti-inflammatory medications such as ibuprofen, or gastrointestinal illness should change the plan.
During travel, “drink water” is necessary but not always sufficient. People on lithium generally need consistent fluid intake and a consistent diet, including sodium, unless a clinician has advised otherwise. In practical terms, that may mean carrying electrolyte drinks, taking cooling breaks seriously, avoiding unnecessary sauna or hot-spring exposure in extreme weather, building rest into the day, and avoiding the urge to treat heat symptoms as something to power through.
There is a psychological piece here as well. Many of us who live with bipolar disorder do not want to feel medically fragile. We want to be spontaneous. We want to participate. We want to say yes to the tour, the hot spring, or the hike.
But self-protection is not fragility—it’s what allows the life we want to continue.
My trip to Italy was wonderful. I’m grateful for it. But I also came home with a renewed respect for the medication that helps keep me well.
Lithium has helped give me a life I once feared I might not have. A life in which I can travel, work, write, teach, love, and participate in the world. That is why I will remember that the medication that has been my salvation comes with real risks that change with context.