So my kids usually head outside prepared for the weather in a thin down jacket, or hoodies or long sleeves. If it’s really cold like yesterday in the 30s, they’re wearing gloves and hats. As they start to play, they peel everything off to avoid getting sweaty, and they play their hearts out until That ice cold air starts to hit the sweat. Thats when they eventually put the jacket back on. It’s not the sweat under the jacket that makes them sick. Having wet moisture on their skin that cools them in ice cold air that lower their defenses a little bit. ONLY a virus circulating inside of their overpacked classrooms or a bacterial infection Can actually make them sick. Being outside is one of the best things for them.

No, but if he’s sweating the jacket is inappropriate for the weather.

Actually, yes, sweat can make your body react negatively to cold. The body loses heat easier when wet so if you sweat a lot and then take a break in the cold air your body will quickly lose vital heat. This can be dangerous. Hypothermia can occur. If your body is fighting off hypothermia then yes of course your immune system can be weakened. The problem isn’t sweating while active per se. The problems occur once you stop the activity and then find yourself cold and wet.

JFC are you serious? Sweat causing illness? Seriously use those brain cells.

It doesn't cause illness but if your kid is sweating they should tale off their coat. My kids mostly wear fleece zip ups or hoodies all year. The coat is saved for if it snows.

we live in a northern state and it was pretty mild today. The kids shed their jackets in the afternoon on someone’s porch annd ended up at another house in the neighborhood, and once the sun went down we all had to run their jackets over. It’s normal and ok to take off a jacket or coat or playing or put it back on- just practice the habit of actually retrieving it.

If this were true, every person who plays a winter sport at a high level would be dead from pneumonia.

The cough is from bacteria and viruses and he’s probably catching it at school.

If they’re sweating in their coat, it’s not appropriate for the weather. A kid standing still at the bus stop for 15 minutes in the winter in Northern VA can wear a puffy coat but the truth is that those big puffy coats are made for kids in MN, VT or Canada. A kid running around in any temperature above 40 is fine in a fleece, thin primaloft jacket, or sweatshirt.

Bacteria and viruses are the cause.

Winter jackets and outdoor/playground warmth - is it better to wear thin and be less sweaty or buy warm and sweat? Does the moisture from sweat cause illness?

DS tends to develop deep coughs each winter, has had pneumonia this season and I am curious if playing outdoors sweaty is a possible cause?

He plays outside all season from sun up to sun down on weekends and walking to/from school during the week along with recess.