Very few of us don't like being outdoors enjoying fresh air and a little sun, especially in the Northern regions as winter begins to fade and gives way to warmer weather. Which bring me to the topic of sweating and sun protection. As a pharmacist I often tell patients to put on a sunscreen 15 to 30 minutes before going outside and reapply after swimming or sweating significantly. There are a number of other factors to bare in mind when purchasing or using a sunscreen.
For people that sweat a lot, particularly individuals that have facial hyperhidrosis, it is important to use a 'water resistant' product. Excessive sweating wears away the sunscreen so a water resistant formulation becomes important. Look for sunscreens that remain effective for 80 minutes when sweating or swimming. Less resistant products will only offer 40 minutes of water resistance. Sunscreens should be applied at least every 2 hours and more often if you are sweating or in and out of the water. Consult the product label for directions related to when to reapply. Make sure you choose a "broad spectrum" sunscreen - these offer protection against both types of radiation, that is, UVA and UVB. Most sunscreens will mention 'broad spectrum' on their label. Sunscreens typically offer UVB protection but they should also include an agent that screens from UVA. The latter type of rediation is responsible for causing photoaging and premature skin wrinkling. Try to remember the word 'benzone'. An ingredient that finishes with this word ending is a UVA sunscreen (e.g. avobenzone, oxybenzone, or sulisobenzone). Finally, be careful if you are out between the hours of 10 and 2 p.m. as this is the period when the sun's rays are most intense.