What does heat intolerance feel like with hyperthyroidism?

You may feel hot when people around you are comfortable, become sweaty with light activity, or wake feeling overheated. Warm skin, damp clothing, flushing, a faster heartbeat, shakiness, trouble sleeping, and restlessness can occur alongside the heat sensation. Symptoms may be stronger in warm rooms or after exercise, but they can also appear while sitting still.

Hyperthyroidism increases the body's activity and heat production, which can make cooling less effective. Heat intolerance alone does not establish the cause; medicines, infection, hormonal changes, and other conditions can also affect temperature control.

Move to a cooler room, loosen extra layers, drink water regularly, and use a fan or cool cloth. Choose breathable clothing and pause strenuous activity if you feel overheated. Record when the sensation occurs and note sweating, palpitations, tremor, weight change, diarrhoea, or sleep changes. Arrange a clinical assessment if the symptom is new, persistent, or accompanied by other signs of an overactive thyroid; testing can help identify the cause.

Seek urgent help for overheating with confusion, fainting, severe weakness, chest pain, severe breathlessness, or a very fast or irregular heartbeat. Contact a clinician promptly if sweating and heat intolerance come with worsening tremor, repeated vomiting, marked agitation, or an inability to keep fluids down.

Ask whether your symptoms fit thyroid overactivity, which tests are appropriate, and whether any medicine or supplement could be contributing. You can also ask how to manage exercise and heat exposure while the cause is being assessed.