Night sweats can be common — anxiety, stress, and sleep problems can cause them even in healthy men. But in rare cases, they could be a sign of cancers such as lymphoma, leukemia, kidney, and thyroid cancer.

Just as your body heats up when it fights an infection, your immune system ramps up to tackle other threats including cancer, Arend explains. If you notice night sweats are becoming a regular occurrence (even after you kick off the thermal sheets) and they come with other symptoms (unexplained weight loss or fever), make an appointment with your doc.

A rare endocrine tumor responsible for heat intolerance is pheochromocytoma, which is a catecholamine or “adrenaline” secreting tumor. It can produce episodic symptoms that are kind of like your “fight or flight” response, Mohan says.

The feeling of being hot all the time could be from carcinoid syndrome, a disease caused by some neuroendocrine tumors which typically arise in the gastrointestinal tract,. adds Mohan. These can also come with symptoms such as flushing of the face, watery diarrhea, wheezing, or shortness of breath when these tumors liberate serotonin and other substances into your system. If you feel you're hot all the time and have additional symptoms that you don't usually experience, definitely see a doctor.