The electromagnetic (EM) spectrum is the range of all types of EM radiation. Radiation is energy that travels and spreads out as it goes  the visible light that comes from a lamp in your house and the radio waves that come from a radio station are two types of electromagnetic radiation.
According to my doctor, 4 hours. You can switch them up. Take acetaminophen, (Tylenol), then wait 4 hours and take Ibuprofen, wait another 4 hours and take acetaminophen and sâ¦o on.
Don't Wait to Medicate. Take (or give your child) a dose of ibuprofen (for example, Advil) as soon as you see signs of sunburn and keep it up for the next 48 hours, Schmitt advises. It cuts back on the swelling and redness that is going to occur and might prevent some long-term skin damage.