Study Finds Women's Resting Body Temperature Rises From Age 18 to 42

Women experience a steady rise in resting body temperature from age 18 to 42, according to a re-analysis of data collected in a 1990s study. Researchers examined daily oral or rectal temperature measurements taken by more than 750 participants who recorded readings each morning upon waking.

The data showed temperatures were lower in the first half of the menstrual cycle and higher after ovulation.

The re-analysis found that each additional year of age corresponded with a small temperature increase across both halves of the menstrual cycle. 05°C higher than those aged 18 to 34. Marie Gombert-Labedens at SRI International said the temperature signal may contain useful health information.

The study excluded participants using hormonal contraception or diagnosed with certain hormonal conditions.

Gombert-Labedens said further research is needed to determine the cause, which may involve hormonal changes. She noted that temperature-sensing wearables could eventually identify patterns linked to perimenopause, biological ageing, or conditions such as ovarian cancer. Other studies have reported that body temperature tends to decline after menopause and approach levels observed in men.