BOLSAC in the sauna
13 peer-reviewed studies

Ice the boys.
Keep the gains.

Sauna kills sperm. BOLSAC keeps your balls cool so you get all the health benefits without nuking your fertility.

Get the Complete Pack → See the Science
€35 Complete Pack

Sleeve + 3 Ice Packs · Free shipping NL · 30-day guarantee

BOLSAC cooling sleeve with ice pack
The Science

Sauna is elite-tier health optimization.

20-year Finnish study, 2,315 men. The numbers speak for themselves.[1]

40%

Lower All-Cause Mortality

4-7 sessions/week vs. 1/week [1]

50%

Less Fatal Heart Disease

20-year follow-up [2]

66%

Lower Dementia Risk

Frequent vs. occasional use [5]

61%

Reduced Stroke Risk

Neurology 2018 [3]

The Problem

Sauna is cooking your boys.

Your balls hang outside your body for a reason: sperm needs 34°C. Your sauna runs at 80-100°C. Do the math.

-14%

Sperm per °C rise

Every degree of scrotal heating tanks your count [8]

2x/wk

Is all it takes

Just twice a week for 3 months significantly impairs sperm count and motility [8]

3-6 mo

To recover

Full spermatogenesis cycle needed to normalize after you stop sauna entirely [10]

72%

Motility Drop

Sperm motility tanks from regular unprotected sauna use [8]

The Fix

Ice the boys. Keep the gains.

Scrotal cooling reverses heat-induced fertility damage. Proven in clinical research.[11]

01

Freeze the Ice Pack

2 hours in the freezer. Medical-grade gel stays cold your entire session.

02

Slide Into the Sleeve

Ice pack goes in the mesh pocket. Drawstring waist. Athletic cut. Locked in.

03

Sauna as Usual

Your body gets 80-100°C. Your boys stay at 34°C. Simple.

BOLSAC ice pack
Shop

Protect what matters.

Free shipping in NL. 30-day money-back guarantee. No questions asked.

BOLSAC Complete Pack

Complete Pack

Sleeve + 3 Ice Packs

€35

everything you need

  • 1x Cooling Sleeve
  • 3x Ice Packs
  • Always have packs freezing
  • Free shipping NL
BOLSAC Sleeve

The Sleeve

Cooling sleeve only

€25

BYOI (bring your own ice)

  • 1x Cooling Sleeve
  • Quick-dry fabric
  • Drawstring waist
  • Free shipping NL
3 Ice Packs

3 Ice Packs

Refill set

€15

per set of 3

  • 3x Ice Packs
  • Medical-grade gel
  • 20+ min cooling each
  • Free shipping NL
Reviews

The boys are grateful.

★★★★★

"Urologist told me to quit sauna while trying for kids. Got a BOLSAC instead. Sperm analysis came back normal. Legend product."

MK
Marcus K.
Verified Buyer
★★★★★

"Thought it was a joke. Three months in -- most underrated piece of gym gear I own. Ice packs last my entire session."

JR
Jake R.
Verified Buyer
★★★★★

"Sauna 5x a week. Wasn't going to stop. Found out about the fertility thing and freaked out. BOLSAC was a no-brainer."

DT
Daniel T.
Verified Buyer
FAQ

Quick answers.

Yes. Research shows just 2 sessions per week for 3 months significantly tanks sperm count, motility, and quality. Your balls need 34°C. Your sauna is 80-100°C. [8]

20-25 minutes in full sauna heat. That covers a standard session. The Complete Pack has 3 packs so you always have backups in the freezer.

Athletic quick-dry fabric, drawstring waist, mesh lining prevents direct ice contact. You forget you're wearing it after a minute.

Yes. Scrotal cooling has been clinically shown to significantly increase sperm concentration, motility, and quality. [11]

S, M, L, and XL. The drawstring waist adds extra adjustability. You pick your size at checkout.

  1. Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Internal Medicine. 2015;175(4):542-548.
  2. Laukkanen T, Kunutsor SK, Khan H, et al. Sauna bathing is associated with reduced cardiovascular mortality and improves risk prediction in men and women. BMC Medicine. 2018;16:219.
  3. Kunutsor SK, Khan H, Zaccardi F, et al. Sauna bathing reduces the risk of stroke in Finnish men and women. Neurology. 2018;90(22):e1937-e1944.
  4. Zaccardi F, Laukkanen T, Willeit P, et al. Sauna bathing and incident hypertension. American Journal of Hypertension. 2017;30(11):1120-1125.
  5. Laukkanen T, Kunutsor S, Kauhanen J, Laukkanen JA. Sauna bathing is inversely associated with dementia and Alzheimer's disease. Age and Ageing. 2017;46(2):245-249.
  6. Janssen CW, Lowry CA, Mehl MR, et al. Whole-body hyperthermia for the treatment of major depressive disorder. JAMA Psychiatry. 2016;73(8):789-795.
  7. Laukkanen JA, Laukkanen T, Kunutsor SK. Cardiovascular and other health benefits of sauna bathing: a review of the evidence. Mayo Clinic Proceedings. 2018;93(8):1111-1121.
  8. Garolla A, Torino M, Sartini B, et al. Seminal and molecular evidence that sauna exposure affects human spermatogenesis. Human Reproduction. 2013;28(4):877-885.
  9. Saikhun J, et al. Effects of sauna on sperm movement characteristics of normal men. International Journal of Andrology. 1998;21(6):358-363.
  10. Shefi S, Tarapore PE, Walsh TJ, et al. Wet heat exposure: a potentially reversible cause of low semen quality. International Brazilian Journal of Urology. 2007;33(1):50-57.
  11. Jung A, Eberl M, Schill WB. Improvement of semen quality by nocturnal scrotal cooling. Reproduction. 2001;121(4):595-603.
  12. Pilch W, et al. Effect of a single Finnish sauna session on white blood cell profile and cortisol levels. Journal of Human Kinetics. 2013;39:127-135.
  13. Ernst E, Pecho E, Wirz P, Saradeth T. Regular sauna bathing and the incidence of common colds. Annals of Medicine. 1990;22:225-227.

Your body deserves the heat.
Your boys deserve the cold.

13 studies. One solution. Don't overthink it.

Get Your BOLSAC →

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