Ugh... Oh my God... Okay, let's just clear up some misinformation you seem to have acquired first: Human beings have never set foot on Mars, we've only sent robots there. Human beings have probably never been to the Moon either, but that's debatable. Secondly, seasons are not caused by temperature changes in the Sun, they have to do with the axial tilt of our planet as it orbits around the Sun. Since the Earth is "crooked", one hemisphere is always warmer and one is always colder, depending on which is closer to the Sun. The Sun's surface temperature averages at about 10,340 degrees Fahrenheit ALL YEAR ROUND.
Now let's answer your question. The answer you're looking for is: ABSOLUTELY NOT. This is because:
1. The Sun is not a solid object. It's made mostly of hydrogen and helium plasma with traces of heavier elements. You could not walk on it.
2. The Sun is unimaginably radioactive, and very hot. About 10,340 degrees on the surface, as mentioned above. But around the Sun there is also an energy field called the Corona that's temperature is in excess of 900,000 degrees! There is no known substance that wouldn't be vaporized by this kind of heat instantly.
3. For the sake of argument, let's say you had a ship and spacesuits that could take this heat and radiation, and you did have something to walk on at the Sun's surface. You'd still die. The Sun has about 330,000x the mass of the Earth, and thus has faaaaar stronger gravity. You'd be crushed to basically nothing by your own weight.
So, no, it is absolutely impossible to walk on the Sun. It can't happen, and it never will. No question. So I hope this helped answer your question.