70 years later, this healthier option is still not officially available to the public. Is it because there is no money in simple heat, compared to billions from selling pills? And because traditionally, the burden and responsibility of contraception has fallen on women?

It makes no sense to target women's internal organs, causing hormonal disruptions and other trouble, when it is so easy to pause sperm production by applying a little heat to men's testes - that conveniently hang outside the body.

So at last, we are bringing Dr Voegeli's method to the world. With a heating cup, which is more convenient than a bucket of water:

1. The man wears a heating cup an hour a day for 3 weeks, until sperm are gone.

2. A cheap USB microscope lets you verify, together at home, that they are indeed no longer there.

3. Once gone, it takes them 10 weeks to come back. To keep them away longer, heat again after 7 weeks.