When a couple has trouble conceiving, it’s easy to assume the problem lies with the woman. But male infertility plays a role in a large percentage of infertility cases. For a man to successfully conceive with his partner, he needs to have healthy sperm in sufficient quantities.
Many factors can affect sperm count and quality. One of the most important is temperature. Sperm production is highly sensitive to temperature. This means that fever or other sources of heat exposure can affect spermatogenesis (sperm production) and semen parameters like sperm count, motility, and morphology (shape).
So, what body temperature kills sperm? How does fever affect sperm? What about hot tubs, saunas, and laptops? We’ll answer these questions and more. We’ll also give you some actionable tips to minimize heat exposure and improve your sperm health.
Understanding Fever and Its Impact on Sperm
Let’s talk about fever and how it can impact sperm.
What Constitutes a Fever?
First, what is a fever? Typically, doctors say a fever is present when your body temperature is 99–100ºF or higher. Usually, fevers are caused by infections, like the flu, or inflammatory conditions.
Your body is designed to maintain a core temperature around 98.6ºF. But sperm production is a little more sensitive to temperature changes.
How Fever Affects Sperm Production
Optimal sperm production happens at a temperature that’s about 3.5 to 7 degrees F cooler than your normal body temperature. That means the ideal temperature for sperm production is around 93.2ºF.
When you have a fever, it increases the temperature in your scrotum, and this can impair sperm production. Specifically, fever can lower sperm count and sperm quality and increase genetic abnormalities.
Research shows that elevated temperatures in the scrotum can damage sperm production through several means. While maintaining a healthy lifestyle is crucial, some explore natural remedies; however, it’s important to approach these with caution and research, such as understanding how to prepare aloe vera juice for fertility correctly. For instance, high temperatures may lead to apoptosis (programmed cell death) of spermatogenic cells. Heat can also increase oxidative stress and sperm DNA damage.
Fever’s Impact on Sperm Quality Parameters
Having a fever, especially if it lasts for several days and is above 101°F, can significantly reduce sperm count and sperm quality.
One study showed that sperm concentration can decline by as much as 7% within 6 weeks after a fever of 102.2°F or greater that lasts for 3 or more days.
Sperm motility and morphology can also decrease for weeks after a fever. Plus, sperm DNA fragmentation can increase significantly after a fever.
Quantifying the Effects of Fever on Sperm Parameters
So, we know that heat can affect sperm, but what does the science say about fevers and their impact on sperm health? Let’s dive into some specific data.
Fever and Sperm Count
Studies show a pretty clear link between fever and a drop in sperm concentration. For example, one study of 27 men found that sperm concentration can decrease by up to 8.5% for each day someone has a fever. Another study showed a 32–35% decrease in sperm concentration for men who had a febrile illness.
There are also case studies illustrating this point. One case report described an infertility patient whose sperm concentration dropped to less than half after his fever went away.
Fever and Sperm Motility & Morphology
It’s not just the number of sperm that can be affected; fever can also impact how well they move (motility) and their shape (morphology). Statistics show that progressive motility (how well sperm swim forward) can decrease by up to 23% around 6 weeks after a fever.
As for morphology, studies have shown over a 7% decrease in the percentage of sperm that are considered morphologically normal after a fever. One study of 27 men also showed an increase of 20.4% in immotile sperm (sperm that don’t move) following a fever.
Fever and Sperm DNA Fragmentation
Perhaps even more concerning is the potential for fever to damage sperm DNA. Sperm DNA fragmentation (damage to the genetic material within the sperm) can increase significantly after a fever. Data shows that in one case, 36% of sperm had damaged DNA just 18 days after a man had a 1-day flu fever.
Other Sources of Heat and Sperm Quality
Okay, so we know sperm don’t like it hot. What other things can raise the temperature around your testicles and potentially harm sperm?
Hot tubs, saunas, and hot showers
Hot tubs and saunas raise your overall body temperature, including the temperature in your scrotum. The average hot tub runs between 97 and 104 degrees Fahrenheit (36-40 degrees Celsius). Saunas are even hotter, with average temperatures hovering around 180-195 degrees Fahrenheit (82-90.5 degrees Celsius).
Research has shown that regular hot tub use can negatively impact sperm. One study found that men who used hot tubs above 98.4 degrees Fahrenheit for at least 30 minutes a week for three months had 22% lower sperm motility.
The bottom line? Avoid hot tubs above 95 degrees Fahrenheit and saunas altogether if you’re trying to conceive.
Lifestyle Factors: Laptops, Car Seats, and Underwear
Believe it or not, even how you use your laptop or what kind of underwear you wear can affect sperm quality.
Placing a laptop directly on your lap can increase scrotal temperature. Heated car seats, while comfy, can do the same. It’s best to avoid heated car seats if you’re concerned about sperm health.
And then there’s the boxers vs. briefs debate. One study of 656 men found that those who primarily wore boxers had 25% higher sperm counts than those who wore tighter underwear. Wearing loose-fitting boxer shorts may improve sperm parameters by allowing for better airflow and temperature regulation.
Occupational Heat Exposure and Prolonged Sitting
Certain professions that involve high heat exposure, like occupational drivers, bakers, and military sailors, can also negatively impact sperm. Prolonged sitting, regardless of your profession, can also increase scrotal temperature.
If you have a job that requires you to sit for long periods, try to sit with your legs somewhat apart to promote airflow and keep things cool.
Recovery and Actionable Tips
The good news is that the effects of a fever on your sperm are usually temporary.
Sperm Recovery Time After Fever
If you’ve had a fever, your sperm should return to normal levels within about 2 to 4 months. Keep in mind that the spermatogenesis cycle, the process of creating new sperm, takes about 72 days.
When to Get a Semen Analysis
If you’re concerned about your sperm count after a fever, it’s best to wait at least two months before getting a semen analysis. For optimal results, it’s important to follow guidelines on how to get the best sperm sample for IVF. This allows enough time for your body to produce healthy sperm again.
Also, remember to abstain from ejaculation for 2–5 days before you produce a sample for testing. This helps ensure accurate results. When the time comes, consider your choice of lubricants, and understand the implications of ingredients like hydroxyethylcellulose in lube, with respect to texture, safety, and fertility.
Practical Tips for Maintaining Scrotal Temperature
Here are some simple things you can do to keep your scrotum cool:
- Use cooler water when you shower or bathe.
- Place laptops on a desk or use a lap desk to create a barrier.
- Wear loose-fitting boxer shorts instead of briefs.
- If you sit for long periods, get up regularly to cool down.
- Think about using a standing desk if you work at a desk job.
Frequently Asked Questions
Does having a cold affect your sperm?
Generally, a mild cold shouldn’t have a significant impact on sperm production or quality. However, a high fever (over 101°F or 38.3°C) associated with a more severe illness could temporarily affect sperm production. It’s usually a short-term effect.
What are signs of healthy sperm?
Signs of healthy sperm are typically assessed through a semen analysis. Key indicators include sperm count (concentration), motility (how well they move), and morphology (their shape). A normal semen analysis suggests good sperm health, but it’s just one piece of the fertility puzzle.
Do hot showers reduce sperm count?
Frequent exposure to high temperatures, like from hot tubs or very hot showers, can negatively impact sperm production. Sperm thrive at a temperature slightly cooler than body temperature. Regular, prolonged exposure to heat may temporarily lower sperm count and motility.
How long does it take sperm to reach the egg?
After ejaculation, sperm can reach the egg in as little as 30 minutes, but it can also take several hours. Sperm need to travel through the cervix, uterus, and fallopian tubes to reach the egg. Only the strongest and most motile sperm will make it.
Can wearing tight pants affect male fertility?
While the research isn’t conclusive, consistently wearing tight-fitting pants could potentially affect male fertility. The idea is that tight pants may raise the temperature around the testicles, which, as we discussed, isn’t ideal for sperm production. Opting for looser-fitting underwear and pants is generally recommended if you’re concerned about fertility.
To conclude
Your testicles are outside your body for a reason: Sperm need a cooler environment than your internal organs can provide. If your testicles get too hot, it can negatively impact both the quantity and quality of your sperm.
As we’ve seen, fevers and other sources of heat — like hot tubs and tight underwear — can raise the temperature of your testicles and disrupt sperm production. The good news is that these effects are usually temporary, as long as you give your body time to recover.
To protect your sperm, consider the actionable tips we’ve provided to reduce heat exposure. These include wearing loose-fitting underwear, avoiding prolonged exposure to heat sources, and managing fevers promptly.
If you have any concerns about your fertility or sperm health, it’s always a good idea to consult with a healthcare professional for personalized advice and evaluation.