Does Body Heat Affect Male Fertility? Discover The Connection


Infertility is a growing concern, with around 1 in 8 couples having difficulty conceiving. Male infertility accounts for 30-50% of cases, and one potential culprit is body heat. Elevated temperatures around the genital area can impair sperm production and function. Understanding how body heat impacts male fertility, and what men can do to optimize temperatures, may improve the chances of conception.

How Does Body Heat Affect Male Fertility? 

Sperm production thrives in cooler temperatures. The testes are located outside the body in the scrotum specifically to maintain a temperature around 2-4°C lower than the core body temperature. However, lifestyle factors like sedentary office jobs, tight underwear, hot tubs, and fevers can all raise scrotal temperatures. This heat impairs spermatogenesis and reduces sperm count and motility. 

Body Heat And Male Fertility

Prolonged heat exposure triggers oxidative stress and DNA damage in sperm. Hyperthermia also causes protein misfolding in sperm cells. Both processes hamper sperm function and increase abnormal morphology. The effects can last up to two months after heat exposure due to the duration of the sperm production cycle.

Men exposed to sources of heat like kilns, furnaces, or ovens show higher rates of infertility. One study found that 93% of male bakery workers had impaired sperm quality. Hot baths have also been linked to reduced fertility in men. 

What Is The Ideal Body Temperature For Sperm?

To optimize fertility, experts recommend keeping the testes 2-4°C cooler than the core body temperature. Core body temperature is generally around 37°C. Therefore, the ideal scrotal temperature is between 33-35°C. 

Scrotal temperature can vary based on ambient temperatures and clothing. Tighter underwear like briefs trap heat around the genitals. Loose boxer shorts or going commando allow more airflow and cooling. The scrotum also naturally descends and retracts in response to heat to regulate sperm temperature. 

A normal oral temperature is considered up to 37.5°C. Fevers above 38°C can already impact sperm. Wet heat like hot tubs and saunas pose an even greater risk due to full immersion of the testicles. 15 minutes can already affect sperm viability and motility.

How To Improve Sperm Quality?

Here are some tips men can follow to reduce genital heat exposure and improve sperm health:

  • Wear loose, cotton boxer shorts instead of tight briefs. Avoid saunas and hot baths.
  • Avoid extended sedentary time sitting with your legs closed. 
  • Sleep naked without thick blankets that can raise the scrotal temperature at night.
  • Treat any fevers promptly with medications to normalize temperature.
  • Keep laptops and heated car seats away from the lap and genitals.
  • Quit smoking and limit alcohol which can compromise fertility.
  • Get regular STD testing and treatment to avoid epididymal inflammation.
  • Take supplements like antioxidants, zinc, and selenium to improve sperm parameters.
  • Manage stress through yoga, meditation, and other relaxation techniques.


Male fertility depends on proper testicular temperatures for healthy sperm production and function. Lifestyle choices that promote heat exposure like frequent hot tub use or wearing tight underwear can impair sperm and reduce a man’s reproductive potential.

Paying attention to keeping the testes cool through loose clothing, regular exercise, and avoiding fever-inducing illness may help safeguard fertility. Implementing healthy habits and sperm-friendly practices can improve a man’s chances of fathering a child.


Q: What are normal sperm parameters?

A: Normal sperm parameters as defined by the World Health Organization are:
– Sperm concentration: 15 million sperm per ml or more 
– Motility: 40% or more motile sperm
– Morphology: 4% or more normal forms

Q: How long does it take for sperm to regenerate after heat exposure?

A: It takes approximately 60-70 days to regenerate new sperm after heat exposure due to the duration of the spermatogenesis cycle. Effects on sperm from transient heat exposure lasts at least a month.

Q: Can hot weather decrease male fertility? 

A: Yes, very hot weather can potentially affect sperm production and quality. Wearing moisture-wicking boxer shorts and staying hydrated may help keep the testes cool during the hot summer months.

Q: Should men avoid hot tubs if trying to conceive?

A: Yes, men trying to conceive should avoid prolonged hot tub use. 15 minutes of hot tub exposure can already impact sperm motility and viability for up to a month.

Q: Are saunas safe for male fertility?

A: No, saunas are not recommended for men aiming to optimize fertility. The extreme dry heat can impair sperm quality and function for months afterward.

Dr. Jun Ren is a dedicated and experienced registered dietitian and nutritionist who is committed to helping people achieve their health goals through personalized nutrition plans. With a passion for promoting healthy eating habits and preventing chronic diseases, Dr. Ren has been able to assist numerous clients in improving their overall quality of life.

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