Always wait a half-hour after eating before swimming
This one has been around for generations and it’s not even clear anymore how it got started.
Yes, it’s true that you can get a stomach cramp if you try to exercise vigorously after eating, but it won’t be a cramp that would impair your ability to swim or to keep your head above water. Chances are if you’ve eaten a big meal, you’re probably not interested in going for a swim anyway. It’s also not clear where the 30-minutes wait window came from either, since it typically takes a lot longer — three to four hours — for the stomach to empty.
A base tan will help prevent sunburns
Contrary to popular belief, a tan does not do a really great job of protecting your skin from skin damage. In fact, the extra melanin the sun produces in your skin offers a sun protection factor (SPF) of only about 2 to 4 — nowhere near the recommended SPF of 15 that helps protect the skin from sunburn and cancer.
When barbecuing burgers, colour is the best way to tell if they’re done
If you’re used to grilling burgers until you no longer see pink, you may not be cooking them enough. Meat can turn brown before all the E. coli and other bacteria are killed. The best way to check for done-ness is to use a digital thermometer to take the temperature in the thickest part of the meat and ensure it’s reached 160ºF (71 C). Even burgers that are still pink inside can be safe to eat if — and only if — they’ve reached this temperature.
When driving, open windows are more fuel-efficient than the A/C
The Society of Automotive Engineers tested a sedan and an SUV, at speeds of 50 km/h, 80 km/h and 110 km/h to see whether the wind drag of opening the windows burned up more gas than the air conditioning system. What they found was that the ambient heat didn’t matter much, nor did the size of the engine or the vehicle. What it really came down to was speed.
When driving at a low speed, say in the city, it’s more efficient to leave windows open, they found. When the speed picks up past 65 km/h though, the wind drag effect really kicks in and you end up using less gas by switching on the air conditioning.