Thanks for the query. Since you are light skinned and red haired, you have more chances of developing freckles. Freckles occur due to increase in pigmentation following exposure to the sun. There are two types of freckles simple freckles and sunburned freckles. The one you have described is of the sunburned freckles type. Reducing the exposure to sun and during sun exposure can prevent these freckles; you could use a sunscreen lotion with an SPF of more than 30. You can also use a skin lightening cream like hydroquinone less than 4%, chemical peels. Hope this helps. If there are any further queries, you can always feel free to ask.
Thank you.