When you have an autoimmune disease, your immune system attacks healthy cells in your body by mistake. While every autoimmune disorder is distinct, many share overlapping features. One common issue is heightened sensitivity to weather. Temperature shifts — bouts of extreme hot and cold, as well as abrupt changes in either direction — can exacerbate symptoms of numerous autoimmune conditions, including hyperthyroidism, lupus and the one I have, multiple sclerosis. These symptom “flare-ups” are usually temporary, but they can still be a drag.
What’s tricky is that temperature changes can trigger different responses in people with the same autoimmune disorder. “It’s important to recognize that there’s interindividual variability in how symptoms of an autoimmune disease are affected by different weather patterns,” says Dr. Lili Barsky, a hospitalist and urgent care physician. “There is also a lot of subjectivity associated with how patients report flares.”
Fortunately, there are ways to mitigate the severity of weather-induced flare-ups. Here’s an overview of how and why heat and cold exacerbate different autoimmune disorders, and what patients can do to prepare for temperature shifts.
Which autoimmune conditions are exacerbated by temperature changes, and how?
Trigger: Temperature and weather changes, generally
Arthritis causes joint pain and swelling. Some research suggests weather affects arthritis symptoms, particularly in patients with osteoarthritis of the hip, the most common type.
In one 2014 study of arthritis patients, about two-thirds reported increased pain and stiffness in high humidity and cold, wet weather. An earlier study, from 1995, found that younger people with arthritis were more sensitive to temperature-induced pain changes than older ones. And a 2007 study found that changes in air pressure and temperature were associated with arthritic knee pain severity. The prevailing belief is that temperature intensifies arthritis pain by changing the composition of synovial fluid, which lubricates joints for ease of movement.
Hyperthyroidism and hypothyroidism
Trigger: High and low temperatures, respectively
Your thyroid, an endocrine gland in your neck, secretes hormones into your bloodstream to help regulate your metabolism. (Your metabolism and body temperature are directly related.)
People with hyperthyroidism have overactive thyroids (meaning they over-secrete thyroid hormones), while those with hypothyroidism have under-active thyroids. Both conditions make it hard to maintain a normal body temperature, in opposite ways.
- Hyperthyroidism leaves you prone to overheating. High temperatures heighten this sensitivity, spurring symptoms such as stress, shaky hands and excessive sweating.
- Hypothyroidism makes you sensitive to cold, even in summer. Frigid temps can worsen symptoms like depression and fatigue, and compound the challenge of warming up your body, especially your extremities.
Trigger: Heat and sunlight
Lupus targets the joints and skin, and internal organs including kidneys and lungs. It can also cause cognitive issues. Many different factors are known to contribute to the condition, from genetics to hormones. Other factors, like viruses and ultraviolet light, can cause symptoms to flare up.
There’s not much research on the impact of temperature on lupus, but it’s been reported that weather changes, particularly heat spikes, can cause pain and inflammation. A 2019 study found an association between increased Lupus symptoms and changes in weather or air quality, such as intense heat or cold, high humidity, wind and severe air pollution.
Beyond heat itself, excessive UV exposure can trigger rashes, tingling and fatigue in people with lupus. (And even if it doesn’t seem like a sunny day outside, UV rays can slip through the clouds.) “Photosensitivity, or sensitivity of the skin to the sun, is a feature of lupus,” says Barsky. “It can also be a side effect of certain anti-inflammatory medications taken for this autoimmune disease.”
Triggers: Hot and cold temperatures
MS is characterized by damage to myelin, a fatty substance that insulates nerve fibers in the central nervous system. Damaged myelin makes it hard for the nervous system to send signals, causing issues such as muscle pain, weakness and numbness, double vision, impaired mobility and coordination, difficulty processing information and fatigue. I’ve been told to think of damaged myelin like exposed electrical wire: The plastic coating is broken, leaving the wires prone to short-circuiting.
Heat is the most common temperature trigger for those with MS. In fact, in the 19th and 20th centuries, doctors often diagnosed MS based on “a hot bath test.” When patients exhibited worsening neurological symptoms during a hot bath, MS was presumed. More recently, a 2018 study suggested that 60 to 80% of MS patients have heat sensitivity, technically called Uhthoff’s phenomenon. (Increases in body temperature of less than a degree can exacerbate symptoms.) But some MS patients, myself included, are more sensitive to cold.
Experts are still trying to figure out exactly why heat and cold trigger MS symptoms. At a basic level, they believe abrupt temperature shifts slow down MS patients’ already-damaged nerve pathways. Luckily, these effects are usually temporary and unlikely to cause permanent damage.
Trigger: Extreme temperatures
Raynaud’s syndrome is a condition where arteries narrow when blood vessels contract, resulting in numbness, pain and discoloration in the extremities. Typically, a person’s toes, fingers or nose will turn blue or white.
A few different things, including stress, can activate symptoms. But Barsky says extreme cold is the most common trigger. Raynaud’s can also surface in the summer, indicating that the condition might respond to temperature fluctuations in general.
Raynaud’s can develop as a standalone condition. But, in some cases, it occurs as a result of another underlying disease. Lupus is one associated disorder. Another is Scleroderma, a connective tissue disorder that causes hardening of the skin. As many as 85% of Scleroderma patients also have Raynaud’s, which is also characterized by extreme heat sensitivity.
Trigger: High and low temperatures
Sjögren’s syndrome causes dryness in the tear ducts and saliva glands. The disease can also affect other parts of the body, causing pain, swelling, rashes and irritation, fatigue and weakness. About half the time, it occurs alongside other autoimmune conditions such as lupus, rheumatoid arthritis or scleroderma.
Barsky points to a recent study showing that both extreme heat and cold often affect Sjögren’s. Experts aren’t sure why people with Sjögren’s have temperature sensitivities, but Barsky points to a few possible explanations. One popular but unsubstantiated theory, she says, is that decreased barometric pressure can cause joints to swell. Another is that Vitamin D and humidity might also trigger symptoms, but Barsky says studies exploring this idea have been inconclusive. With any autoimmune condition, it’s important to develop coping techniques for symptom flare-ups.
What can you do if heat is a trigger?
If your symptoms flare up in hot weather, Dr. Julia Blank, a family medicine physician at Providence Saint John’s Health Center in Santa Monica, California, recommends staying hydrated (limit diuretics like alcohol and caffeine), avoiding strenuous outdoor activity in the heat, and wearing cool and breathable clothing. Also, she says, “Check pollen counts and air quality alerts before heading outdoors, and consider staying indoors with windows closed if pollen counts are high or air quality is poor,” as studies have linked air pollution to autoimmune inflammation.
If you have an autoimmune condition and get overheated and need to cool down, Dr. Brian Steingo, an expert in multiple sclerosis at the Sunrise Medical Group Florida, recommends taking a cool bath for 20 to 30 minutes. “A cool shower can also help reduce core body temperature following activity or exposure to a hot environment,” he says.
Do what you can to keep your home cool in the summer. If you don’t have air conditioning, your doctor might be able to prescribe it, and it might be tax deductible.
If an autoimmune condition causes you to break out in a rash or experience skin irritation in hot weather, ask your doctor if any topical medication would help relieve your symptoms. Some studies have shown topical CBD oil can help ease skin discomfort from inflammatory diseases. I’ve personally found CBD oil helpful for itching, tingling and hives caused by weather changes.
What can you do if cold is a trigger?
I’m in the minority among people with MS; I can usually tolerate heat but cold weather sends nerve pain shooting through my legs. It’s unbearable, and staying warm is one of the only things that helps mitigate the unpleasant sensations, which present as tingling, itching, aching and stabbing.
If, like me, cold temperatures are a trigger for your autoimmune condition, it can help to be prepared ahead of time. Simple items like heat pads and hot water bottles are an instant source of warmth and they can often provide immediate pain relief. It’s also essential to wear multiple layers when you leave home, especially if impaired mobility can happen during flare-ups. Family members sometimes complain that my house is like a sauna in the winter, but cranking up the thermostat is one of the only tools I have to prevent temperature drops from taking a toll on my health.
In some autoimmune conditions, such as hyperthyroidism, in which cold weather affects hormone levels, a doctor may be able to adjust the dosage of your medication to improve your symptoms.
No matter what, if you have an autoimmune condition and suspect that temperature is a trigger for you, tell your doctor. Describe how your symptoms change in response to temperature. They’ll help you understand what’s happening and come up with a plan to prepare for exposure to triggers and deal with any unavoidable flare ups. Also, consider tracking your responses to temperature over time, to learn whether your symptoms are triggered by particular weather conditions or temperatures.