Health

I don't think so. I'm fairly sure testosterone levels are consistent across climates though I haven't done any research into this

E: if I had to guess this would be a myth started from the fact that some species' sex selection process is influenced by the local temperature. Again, no research done literally the "I made it the fuck up" meme

There's very little reason to "boost your testosterone" unless you are suffering health problems as a result of low testosterone, in which case, your doctor can prescribe you something that will actually work. The vast majority of testosterone boosters on the market without a prescription do diddly squat, they're just marketed at men with body image issues or low self esteem to make money. Your testosterone levels are natural for you, they fluctuate over time, both on the short and long scale, but trying to boost them with natural supplements or magic pants is just a waste of money.