Heated briefs

Spoiler: heated briefs don’t heat. The name comes from the French slip chauffant, and you’ll also see “heated underwear.” They have no wires, no battery, no heating element. They hold the testicles up inside the body, at the base of the penis. It’s body heat, 37°C (98.6°F), that slows down sperm production². So the name is misleading. What the briefs do has a proper name: testicular elevation.

🩲 Which briefs, exactly?

Usually one of these two:

• the briefs with a hole from Toulouse University Hospital (CHU de Toulouse), the ones used in the studies: the penis and the skin of the scrotum go through a hole, and elastic straps keep the testicles up¹
• the jockstrap, sewn by hand, with an adjustable fabric ring, which you can learn to make at sewing workshops⁴

The silicone ring does the same thing, without the fabric. At Otoko, it’s the tool we provide after an information session. None of the three does anything to fertility on its own: your body does the work.

There are also briefs that really do heat, above body temperature. That’s a different method, and not one we teach.

🔥 So why “heated”?

Held up inside the body, the testicles warm up by 1 to 2°C². That difference is enough, because they normally make sperm 2 to 4°C below body temperature³. The word “heated” comes from that effect, even though the briefs themselves give off no heat.

Wondering what the method changes day to day? The protocol: testicles held up 15 hours a day, every day¹. It takes several months for sperm to fall below the contraceptive threshold: fewer than 1 million motile sperm per milliliter. Only a lab test, a semen analysis, can tell you. Until a semen analysis has confirmed that threshold, you still need another method of contraception.

🚪 Where to go from here

The technique, the tools, the protocol, and what the studies say: testicular elevation.

Rather talk it through? A one-hour session on a video call with Sam, in English, on your own or as a couple, pay what you can. Want to see it in person, or sew your own jockstrap? There are workshops in Paris (in French).

Sources