Yes, a market umbrella can be a great help in preventing sunburn. Because sunburn is caused by exposure to the sun, a person can prevent sunburn by reducing this exposure. Sitting under a market umbrella will limit only sun exposure--not your sense of adventure!
No, sunburn is a burn. It kills the surface layer of skin and this will peel off. However, gentle, short and prolonged exposure to the sun (never getting burned in the process) will cause melanin to appear in your skin. This sort of tan is not caused by a burn and is a semi permanent change in your skin (provided exposure to sun is kept up) and this will not peel off. HOWEVER please remember that exposure to the sun (UV rays) is harmful to the skin and can cause skin cancers later in life - bad sunburn is especially dangerous for this!
The green tinge is caused by excessive exposure to light.
A burn on the skin caused by excessive exposure to the sun or other sources of ultraviolet-A and -B radiation.
Heatstroke
Yes, sun poisoning can occur without a sunburn. Sun poisoning is a severe case of sunburn that can cause symptoms like blistering, fever, and chills. It can also be caused by prolonged exposure to the sun without necessarily developing a visible burn on the skin.
There is no such thing as sun cancer. Cancer caused by excessive exposure to ultraviolet rays is skin cancer.
ultra-violet rays cause skin cancerMost times, it is caused by excessive sun exposure.
There is no definite amount of freckles that one can have. Freckles can be natural or caused by excessive sun exposure.
The excess exposure and ultraviolet light dosage can and will result in damage to human tissues. Two forms of damage include burns and inducing cancer causing mutations.
Mutation can be caused by many factors (birth defects, exposure, etc.). It is often times harmful (in birth defects: person with three #23 chromosomes; in exposure: a person handling uranium). (sometimes exposure can often kill off cancer [but then again so can Chemo])
A severe sunburn could potentially lead to skin cancer.